NR-042
Ingredient Atlas entry · Vitamin
Vitamin D3
Cholecalciferol (D3) and ergocalciferol (D2)
A fat-soluble vitamin, also called cholecalciferol, vitamin D or the sunshine vitamin. This page covers only studies in people that measured thinking, memory, mood, stress, sleep, energy, tiredness or quality of life, so it is not all research on vitamin D. Here is every such study we could find, sorted from each study's summary.
- Found in: oily fish, eggs, fortified foods
- Doses range from small daily amounts to large weekly or one-off doses
- Often weeks to months long
The research map
From every paper to the studies that matter
Most research on vitamin D is about bones, blood levels or other health topics. This page counts only studies that gave vitamin D to people and measured thinking, memory, mood, stress, sleep, energy, tiredness or quality of life.
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8,503 papers mention vitamin D.Every record in PubMed, all years
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791 are about people.The rest: 1,075 lab and animal studies, 2,112 reviews, 4,525 on chemistry, farming and more
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262 give vitamin D on its own and measure these topics.87 more give it with calcium, other vitamins or inside a blend
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133 are randomised against a placebo.Randomised controlled trials In a randomised controlled trial, people are put into groups by chance, one taking the treatment and one a placebo or other comparison. Chance spreads differences such as age and health evenly, so a difference between the groups is more likely to be down to the treatment., the strongest kind of study
Bar lengths use a square-root scale so the small numbers stay visible.
At a glance
How much research there is
- 262 studies giving vitamin D to people and measuring these topics
- 133 of them randomised against a placebo A placebo-controlled trial compares a real treatment with a dummy that looks the same, the placebo. People often feel better when they expect to, so comparing against a placebo shows how much of the change comes from the treatment itself.
- 114,179 people taking part, where studies say
- 429 systematic reviews A systematic review searches for every study on a question in a set, written-down way, judges the quality of each and sums up what they show together. Many include a meta-analysis. The Atlas lists these as pooled reviews. pooling the trials
Studies in people, by year published
Vitamin D on its own, in studies that measured thinking, memory, mood, stress, sleep, energy, tiredness or quality of life.
Randomised, placebo-controlled
Other designs
What was measured
What the studies looked at
Each study can measure several things. Choose a topic to see its studies in the list below.
Studies in people with a diagnosed condition are counted here and listed with their population. We describe what they measured, not what they might treat. Most studies also report safety; see below.
Doses and extracts
What was tested, and how much
Doses are shown in micrograms (µg) a day, with 40 IU counted as 1 µg. Many studies gave a weekly, monthly or one-off large dose, so we averaged it per day or show the single dose, which is why some dots sit far to the right. The most common daily figure comes from a weekly dose averaged per day, so it says little about typical use. Doses vary widely between studies, from small daily amounts to large weekly doses, and some studies don't name the form.
Daily amount, one dot per study
Summary read72 studies don't give a daily amount in their summary and aren't shown.
Studies per extract
Named extracts are the maker's brand. "Not named" means the study didn't say.
Every study
All studies in people
Filter the list, then open a study on PubMed. Each row comes from the study's published summary. Only studies that measured the topics named at the top of this page are included, and studies with calcium or other ingredients are counted but not listed.
| Study | Who took part | People | Extract and daily dose | Length |
|---|---|---|---|---|
| Ahl 2026RCT, placebo | Older adults, largely vitamin D sufficient | 2,434 | Cholecalciferol (D3), 80 µg | 260 weeks |
| Vyas 2026RCT, placebo | Older adults in VITAL trial | 929 | Cholecalciferol (D3), 50 µg | 208 weeks |
| Seppälä 2026RCT, active or other control | Healthy infants followed to 24 months (400 vs 1200 IU) | 845 | Cholecalciferol (D3), 30 µg | 104 weeks |
| Frederiksen 2026RCT, active or other control | Mother-child pairs, offspring tested at age 10 | 623 | Cholecalciferol (D3), 70 µg | 17 weeks |
| Seppälä 2026RCT, active or other control | Finnish children aged 6-9 supplemented in infancy (400 vs 1200 IU) | 398 | Cholecalciferol (D3), 30 µg | 104 weeks |
| Sandboge 2026RCT, active or other control | Finnish children aged 6-8 supplemented in infancy (400 vs 1200 IU) | 366 | Cholecalciferol (D3), 30 µg | 104 weeks |
| Yuan 2026RCT, placebo | Older adults with mild cognitive impairment | 360 | Cholecalciferol (D3), 20 µg | 52 weeks |
| Mikola 2026RCT, active or other control | Adults with depressive episode on usual treatment | 281 | Cholecalciferol (D3), 100 µg | 26 weeks |
| Royle 2026RCT, placebo | Healthy children aged 4-11 | 118 | Cholecalciferol (D3), 10 µg | 12 weeks |
| Lee 2026RCT, placebo | Young people with depression and low vitamin D | 108 | Cholecalciferol (D3), 120 µg | 8 weeks |
| Ray 2026RCT, placebo | Perimenopausal women with vitamin D deficiency | 100 | Cholecalciferol (D3) | 26 weeks |
| Schlarbaum 2026RCT, placebo | Vitamin D-deficient depressed adolescents on usual treatment | 92 | Not named, 66 µg | 4 weeks |
| Lalitha 2026RCT, active or other control | Adults with vitamin D deficiency | 87 | Cholecalciferol (D3), 150 µg | 8 weeks |
| Mokhtar Hassan 2026Single-arm or open-label | Children with dyslexia | 80 | Cholecalciferol (D3) | 13 weeks |
| Sultana 2026RCT, active or other control | Neuropsychiatric lupus patients on standard care | 72 | Cholecalciferol (D3), 143 µg | 19 weeks |
| Anamnart 2026RCT, active or other control | Patients with Parkinson disease | 60 | Cholecalciferol (D3), 50 µg | 12 weeks |
| Afacan 2026Single-arm or open-label | Patients with Parkinson disease and low vitamin D | 49 | Cholecalciferol (D3), 188 µg | 13 weeks |
| Hassan 2026RCT, placebo | Vitamin D-deficient male COPD patients | 40 | Cholecalciferol (D3), 286 µg | 26 weeks |
| D'Agata 2026Single-arm or open-label | Young Black women with low vitamin D | 16 | Cholecalciferol (D3), 125 µg | 8 weeks |
| Lönnroos 2025RCT, placebo | Healthy older adults | 2,492 | Cholecalciferol (D3), 40 µg | 260 weeks |
| Shobanke 2025RCT, placebo | Pregnant women with HIV, infant development at 1 year | 2,167 | Cholecalciferol (D3), 75 µg | – |
| Corbett 2025RCT, placebo | Older adults, vitamin D deficient, early cognitive impairment | 620 | Not named | 104 weeks |
| Porto 2025RCT, placebo | Adults with major depressive disorder | 224 | Not named, 179 µg | 26 weeks |
| Loh 2025RCT, active or other control | Hypertensive obese adults with obstructive sleep apnea | 163 | Cholecalciferol (D3) | 16 weeks |
| Pieruccini-Faria 2025RCT, placebo | Older adults with mild cognitive impairment (factorial with exercise) | 161 | Not named, 107 µg | 20 weeks |
| Tan 2025Observational | Older adults with hypertension and mild cognitive deficits | 153 | Not named, 125 µg | 26 weeks |
| Almassri 2025RCT, active or other control | Women with newly diagnosed breast cancer on chemotherapy | 88 | Cholecalciferol (D3), 179 µg | 9 weeks |
| Linfang 2025Single-arm or open-label | Adolescents with anxiety and low vitamin D | 86 | Not named | 12 weeks |
| Cheng 2025RCT, active or other control | Adults with diabetes and vitamin D deficiency | 80 | Not named | 16 weeks |
| Jones 2025RCT, active or other control | African American adults, type 2 diabetes, low vitamin D | 75 | Cholecalciferol (D3), 100 µg | 52 weeks |
| Ignacio-Mejía 2025Single-arm or open-label | Patients with post-COVID-19 condition | 54 | Cholecalciferol (D3) | 9 weeks |
| Kahraman 2025Non-randomised controlled | Children with restless legs syndrome | 46 | Not named | – |
| Hertig-Godeschalk 2025RCT, placebo | Adults with chronic spinal cord injury and low vitamin D | 42 | Cholecalciferol (D3), 43 µg | 52 weeks |
| Diaz-Ruiz 2025Single-arm or open-label | Decompensated cirrhosis with vitamin D deficiency | 39 | Not named | 52 weeks |
| Kodama 2025Single-arm or open-label | Patients with ME/CFS after COVID-19 vaccination | 28 | Not named | – |
| Predescu 2025Non-randomised controlled | Systemic lupus erythematosus patients | – | Cholecalciferol (D3) | 26 weeks |
| Dalibalta 2025Non-randomised controlled | Vitamin D-deficient university students, both groups exercised | – | Cholecalciferol (D3), 125 µg | 10 weeks |
| Kesavan 2025Single-arm or open-label | Gulf War veterans with vitamin D deficiency | – | Not named | – |
| Lv 2024Observational | Pregnant women with vitamin D deficiency | 1,365 | Not named, 20 µg | 25 weeks |
| Vyas 2024RCT, placebo | Older adults in VITAL trial | 743 | Cholecalciferol (D3), 50 µg | 104 weeks |
| Aagaard 2024RCT, active or other control | Pregnant women; children followed to age 10 for autism and ADHD | 623 | Cholecalciferol (D3), 70 µg | 17 weeks |
| Satyanarayana 2024RCT, active or other control | Rural adolescents | 451 | Cholecalciferol (D3), 56 µg | 9 weeks |
| Miao 2024RCT, placebo | Adults with prediabetes | 212 | Cholecalciferol (D3), 40 µg | 24 weeks |
| Zhou 2024Single-arm or open-label | Diabetic peripheral neuropathy patients with low vitamin D | 192 | Cholecalciferol (D3), 125 µg | 12 weeks |
| Ersoy 2024Single-arm or open-label | Women with fibromyalgia | 180 | Cholecalciferol (D3) | 12 weeks |
| Charoenporn 2024RCT, placebo | Adults with post-COVID fatigue or neuropsychiatric symptoms | 80 | Not named, 214 µg | 8 weeks |
| Chassoux 2024RCT, placebo | Drug-resistant epilepsy with low vitamin D | 74 | Cholecalciferol (D3), 137 µg | 13 weeks |
| Intiso 2024RCT, active or other control | Severe acquired brain injury in rehabilitation | 73 | Not named, 25 µg | – |
| AlGhamdi 2024Single-arm or open-label | Patients with major depressive disorder | 72 | Cholecalciferol (D3), 179 µg | 13 weeks |
| Putranto 2024RCT, placebo | Adults with type 2 diabetes and depressive symptoms | 70 | Cholecalciferol (D3), 100 µg | 12 weeks |
| Elfituri 2024RCT, active or other control | Rheumatoid arthritis patients on DMARDs | 68 | Cholecalciferol (D3), 179 µg | 12 weeks |
| Maghbooli 2024RCT, active or other control | Multiple sclerosis patients | 50 | Calcifediol vs cholecalciferol, 50 µg | – |
| Zhao 2024RCT, placebo | Adults with major depressive disorder on antidepressants | 46 | Not named | 30 weeks |
| Wahono 2024RCT, active or other control | Women with systemic lupus erythematosus | 45 | Cholecalciferol (D3), 30 µg | 13 weeks |
| Heidari 2024RCT, placebo | Women with premenstrual syndrome and low vitamin D | 44 | Not named, 89 µg | 16 weeks |
| Mirhosseini 2024RCT, placebo | Children with ADHD receiving neurofeedback | – | Cholecalciferol (D3), 179 µg | 8 weeks |
| Rahman 2023RCT, placebo | Australians aged 60-84, D-Health | 21,315 | Cholecalciferol (D3), 50 µg | 260 weeks |
| Pham 2023RCT, placebo | Community-dwelling adults aged 70 and over, D-Health | 21,315 | Cholecalciferol (D3), 50 µg | 260 weeks |
| Lin 2023Observational | Haemodialysis patients with kidney failure | 1,424 | Not named, 10 µg | – |
| Sandboge 2023RCT, active or other control | Infants given vitamin D, psychiatric symptoms at age 6-8 | 987 | Cholecalciferol (D3), 30 µg | 100 weeks |
| Vyas 2023RCT, placebo | Older adults, VITAL sub-cohort | 720 | Cholecalciferol (D3), 50 µg | 104 weeks |
| Vyas 2023RCT, placebo | Older adults, VITAL sub-study of BDNF | 400 | Cholecalciferol (D3) | 104 weeks |
| Montero-Odasso 2023RCT, placebo | Older adults with mild cognitive impairment | 175 | Cholecalciferol (D3), 107 µg | 20 weeks |
| Wang 2023RCT, placebo | Adults with knee osteoarthritis (5-year follow-up) | 173 | Not named | 104 weeks |
| Zhang 2023RCT, active or other control | University students in winter | 117 | Cholecalciferol (D3), 25 µg | 4 weeks |
| Mahmoodi 2023RCT, active or other control | Women with premenstrual syndrome | 84 | Cholecalciferol (D3) | 6 weeks |
| Yang 2023Single-arm or open-label | School-age children with ADHD and low vitamin D | 69 | Cholecalciferol (D3) | – |
| Alipouri 2023RCT, placebo | Men with migraine and low vitamin D | 48 | Not named | 8 weeks |
| Essa 2023RCT, active or other control | Adults with relapsing-remitting multiple sclerosis | 47 | Cholecalciferol (D3), 179 µg | 12 weeks |
| Turkmen 2023Single-arm or open-label | Vitamin D deficient older women | 30 | Cholecalciferol (D3), 179 µg | 26 weeks |
| Krysiak 2023Non-randomised controlled | Women with euthyroid Hashimoto's thyroiditis | – | Not named | – |
| Muhihi 2022RCT, placebo | Adults with HIV starting antiretroviral therapy | 4,000 | Cholecalciferol (D3), 50 µg | 52 weeks |
| Fernandes 2022RCT, placebo | Adults hospitalised with moderate to severe COVID-19 | 240 | Cholecalciferol (D3), 5,000 µg | 52 weeks |
| Klasson 2022RCT, placebo | Vitamin D deficient advanced cancer patients | 150 | Not named, 100 µg | 12 weeks |
| Penckofer 2022RCT, active or other control | Women with type 2 diabetes and depression | 129 | Cholecalciferol (D3), 179 µg | 26 weeks |
| Rahmani 2022RCT, active or other control | Children with ADHD | 120 | Not named | 12 weeks |
| Said 2022RCT, active or other control | Adults with mild to moderate COVID-19 | 120 | Cholecalciferol (D3), 50 µg | 2 weeks |
| Abiri 2022RCT, placebo | Obese women with mild to moderate depressive symptoms | 108 | Not named, 179 µg | 8 weeks |
| Zaromytidou 2022RCT, active or other control | Older adults with prediabetes | 90 | Cholecalciferol (D3), 89 µg | 52 weeks |
| Mirzaei-Azandaryani 2022RCT, placebo | Pregnant women with low vitamin D | 88 | Cholecalciferol (D3), 100 µg | 18 weeks |
| Amini 2022RCT, placebo | Women with postpartum depression | 81 | Cholecalciferol (D3), 89 µg | 8 weeks |
| Mohammadzadeh Honarvar 2022RCT, placebo | Children with ADHD | 75 | Cholecalciferol (D3), 50 µg | 12 weeks |
| Samadi 2022RCT, placebo | School-aged children with ADHD | 75 | Cholecalciferol (D3), 50 µg | 12 weeks |
| Bagheri 2022RCT, placebo | Smokers with tobacco use disorder | 60 | Not named, 89 µg | 24 weeks |
| Kumar 2022RCT, placebo | Adults with depression and vitamin D deficiency | 59 | Not named, 300 µg | 12 weeks |
| Kaviani 2022RCT, placebo | Adults with mild to moderate depression | 56 | Cholecalciferol (D3), 89 µg | 8 weeks |
| Bahmani 2022RCT, placebo | Women with multiple sclerosis | 40 | Not named, 179 µg | 8 weeks |
| Adel 2022Observational | SLE patients with COVID-19 | 38 | Not named | – |
| Shelef 2022Observational | Elderly psychiatric inpatients with COVID-19 | 14 | Not named, 20 µg | – |
| Kang 2021RCT, placebo | Community-dwelling adults 60+ (VITAL substudies) | 4,218 | Cholecalciferol (D3), 50 µg | 146 weeks |
| Bahrami 2021Single-arm or open-label | Adolescent girls | 940 | Cholecalciferol (D3), 179 µg | 9 weeks |
| Helde Frankling 2021RCT, placebo | Palliative cancer patients with low vitamin D | 244 | Cholecalciferol (D3), 100 µg | 12 weeks |
| Miller 2021Single-arm or open-label | Children with ADHD and low vitamin D | 222 | Not named | 4 weeks |
| Larsen 2021RCT, placebo | Vitamin D insufficient adults (secondary RCT analysis) | 189 | Not named, 71 µg | 17 weeks |
| Rajabi-Naeeni 2021RCT, placebo | Women with pre-diabetes and low vitamin D | 168 | Not named, 89 µg | 8 weeks |
| Gaughran 2021RCT, placebo | Adults with first-episode psychosis | 149 | Cholecalciferol (D3), 100 µg | 26 weeks |
| Wang 2021Non-randomised controlled | Post-stroke fatigue patients with low vitamin D | 139 | Cholecalciferol (D3), 15 µg | 13 weeks |
| Rahnemaei 2021RCT, placebo | Women with primary dysmenorrhea and vitamin D deficiency | 116 | Cholecalciferol (D3), 179 µg | 8 weeks |
| Shvartsman 2021Non-randomised controlled | Elderly patients with cerebrovascular disease | 100 | Cholecalciferol (D3), 200 µg | 12 weeks |
| Han 2021RCT, placebo | Critically ill adults with vitamin D deficiency | 95 | Cholecalciferol (D3), 13,500 µg | – |
| Pinzon 2021RCT, active or other control | Patients with diabetic peripheral neuropathy | 68 | Not named, 125 µg | 8 weeks |
| Rezaei 2021RCT, active or other control | Acute ischemic stroke patients | 60 | Cholecalciferol (D3), 7,500 µg | – |
| Neriman 2021Single-arm or open-label | Schizophrenia patients with low vitamin D | 52 | Not named | – |
| Torrisi 2021RCT, active or other control | Stroke patients in neurorehabilitation | 40 | Cholecalciferol (D3), 50 µg | 12 weeks |
| Magro 2021Single-arm or open-label | Adults with SLE and low vitamin D | 31 | Cholecalciferol (D3), 200 µg | 52 weeks |
| Khedmati Zare 2021RCT, active or other control | Breast cancer survivors doing yoga | 30 | Not named, 100 µg | – |
| Ayyıldız 2021Single-arm or open-label | Men with mild obstructive sleep apnea | 19 | Cholecalciferol (D3), 179 µg | 8 weeks |
| Maureen Sheean 2021Single-arm or open-label | Women with metastatic breast cancer and low vitamin D | 11 | Cholecalciferol (D3) | 8 weeks |
| Rosenberg 2021RCT, placebo | Adults aged 70+ (DO-HEALTH news summary) | – | Cholecalciferol (D3) | – |
| Okereke 2020RCT, placebo | Adults 50+ without depression, VITAL-DEP | 18,353 | Cholecalciferol (D3), 50 µg | 276 weeks |
| Bischoff-Ferrari 2020RCT, placebo | Adults 70+ without major comorbidities | 2,157 | Cholecalciferol (D3), 50 µg | 156 weeks |
| Rai 2020Single-arm or open-label | Women with easy fatigue and low vitamin D | 1,200 | Cholecalciferol (D3) | 5 weeks |
| Sass 2020RCT, active or other control | Pregnant women and their offspring | 623 | Cholecalciferol (D3), 70 µg | 17 weeks |
| Allahyari 2020Single-arm or open-label | Adults given vitamin D, neuropsychological predictors | 619 | Not named, 179 µg | 9 weeks |
| Zajac 2020RCT, placebo | Healthy older adults | 436 | Cholecalciferol (D3); Ergocalciferol (D2) mushroom, 15 µg | 24 weeks |
| Yang 2020RCT, placebo | Older adults with mild cognitive impairment | 183 | Not named, 20 µg | 52 weeks |
| Yosaee 2020RCT, placebo | Overweight adults with mild-moderate depressive symptoms | 140 | Not named, 50 µg | 12 weeks |
| Libuda 2020RCT, placebo | Children and adolescents with depression and vitamin D deficiency | 113 | Cholecalciferol (D3), 66 µg | 4 weeks |
| Hansen 2020RCT, placebo | Healthy adults in winter | 86 | Not named | – |
| Khalighi Sikaroudi 2020RCT, placebo | Adults with diarrhea-predominant IBS | 74 | Cholecalciferol (D3), 179 µg | 9 weeks |
| Ghaderi 2020RCT, placebo | Patients on methadone maintenance treatment | 64 | Not named, 89 µg | 24 weeks |
| Alghamdi 2020RCT, active or other control | Adults with major depressive disorder on standard care | 62 | Cholecalciferol (D3) | 13 weeks |
| Njoku 2020Observational | Stroke survivors with fatigue | 58 | Not named | – |
| Kaviani 2020RCT, placebo | Adults with mild to moderate depression | 56 | Cholecalciferol (D3), 89 µg | 8 weeks |
| Ramezani Ahmadi 2020RCT, placebo | Active adult males | 46 | Cholecalciferol (D3), 50 µg | 12 weeks |
| Vellekkatt 2020RCT, placebo | Major depression with vitamin D deficiency | 46 | Not named, 7,500 µg | – |
| Dougherty 2020RCT, active or other control | Children with sickle cell disease and healthy children | 44 | Cholecalciferol (D3), 175 µg | 12 weeks |
| Tutuncu 2020Single-arm or open-label | Adults with restless legs syndrome and vitamin D deficiency | 35 | Not named, 179 µg | 8 weeks |
| Sharma 2020RCT, placebo | Acute moderate-severe traumatic brain injury ICU patients | 35 | Not named, 3,000 µg | – |
| Sharifan 2020Non-randomised controlled | Adults with abdominal obesity and insomnia | 29 | Cholecalciferol (D3), 38 µg | 10 weeks |
| Castle 2020RCT, active or other control | Postmenopausal overweight women, low vitamin D | – | Cholecalciferol (D3) | 52 weeks |
| Zhu 2020RCT, active or other control | Depressive patients with low vitamin D | – | Not named | 26 weeks |
| Ates Bulut 2019Observational | Older adults with vitamin D deficiency, geriatric clinic | 560 | Cholecalciferol (D3) | 26 weeks |
| Jorde 2019RCT, placebo | Mid-aged and older adults | 422 | Cholecalciferol (D3), 71 µg | 17 weeks |
| Zheng 2019RCT, placebo | Knee osteoarthritis patients with vitamin D deficiency | 413 | Cholecalciferol (D3), 42 µg | 104 weeks |
| Zhang 2019Non-randomised controlled | Infants of mothers with perinatal depression | 349 | Not named | – |
| Lee 2019Non-randomised controlled | Patients with acute traumatic brain injury | 345 | Not named | 13 weeks |
| Bahrami 2019Single-arm or open-label | Healthy adolescents | 319 | Not named, 179 µg | 9 weeks |
| Schietzel 2019RCT, active or other control | Older adults after joint replacement for osteoarthritis | 273 | Cholecalciferol (D3), 50 µg | 104 weeks |
| Owusu 2019RCT, placebo | Healthy older African-American women (calcium in both arms) | 260 | Cholecalciferol (D3), 87 µg | 156 weeks |
| Jia 2019RCT, placebo | Older adults with Alzheimer's disease | 210 | Not named, 20 µg | 52 weeks |
| Gugger 2019RCT, active or other control | Pre-frail older adults with prior fall | 200 | Cholecalciferol (D3); calcifediol | 52 weeks |
| de Koning 2019RCT, placebo | Older adults with depressive symptoms and low vitamin D | 155 | Cholecalciferol (D3), 30 µg | 52 weeks |
| McCarthy 2019Non-randomised controlled | Active duty soldiers | 152 | Cholecalciferol (D3) | 13 weeks |
| Abdollahi 2019RCT, placebo | Young women with premenstrual syndrome and low vitamin D | 130 | Not named, 25 µg | 12 weeks |
| Dehbokri 2019RCT, placebo | Children with ADHD | 96 | Cholecalciferol (D3), 179 µg | 6 weeks |
| Sharifi 2019RCT, placebo | Mild to moderate ulcerative colitis patients | 90 | Cholecalciferol (D3), 7,500 µg | – |
| Balbaloglu 2019Single-arm or open-label | Women aged 25-45 with low vitamin D | 90 | Not named | 13 weeks |
| Seyedi 2019RCT, placebo | School-aged children with ADHD | 86 | Cholecalciferol (D3), 50 µg | 12 weeks |
| Alavi 2019RCT, placebo | Older adults with moderate to severe depression | 78 | Cholecalciferol (D3), 179 µg | 8 weeks |
| Jalali-Chimeh 2019RCT, placebo | Women with sexual dysfunction and low vitamin D | 76 | Cholecalciferol (D3), 268 µg | 8 weeks |
| Mazahery 2019RCT, placebo | Children with autism spectrum disorder | 73 | Cholecalciferol (D3), 50 µg | – |
| Omidian 2019RCT, placebo | Adults with type 2 diabetes and mild-moderate depressive symptoms | 68 | Not named, 100 µg | 12 weeks |
| Hansen 2019RCT, placebo | Adults with depression on standard treatment | 62 | Cholecalciferol (D3), 70 µg | 24 weeks |
| Denniss 2019RCT, active or other control | Healthy adults | 60 | Not named | 8 weeks |
| Fazelian 2019RCT, placebo | Women with type 2 diabetes, anxiety, low vitamin D | 51 | Cholecalciferol (D3), 89 µg | 16 weeks |
| Wali 2019RCT, placebo | Adults with restless legs syndrome | 35 | Cholecalciferol (D3), 179 µg | 12 weeks |
| Kotb 2019Single-arm or open-label | Relapsing-remitting multiple sclerosis patients | 35 | Cholecalciferol (D3), 250 µg | 52 weeks |
| Eid 2019Non-randomised controlled | Adults with generalized anxiety disorder and low vitamin D | 30 | Not named, 179 µg | 13 weeks |
| Byrn 2019RCT, active or other control | Adults with type 2 diabetes | 30 | Cholecalciferol (D3), 179 µg | 12 weeks |
| Barry 2019RCT, placebo | African-American women with low vitamin D | – | Not named | – |
| Bahrami 2018Single-arm or open-label | Adolescent girls | 940 | Cholecalciferol (D3), 179 µg | 9 weeks |
| Jorde 2018RCT, placebo | Adults, mostly not depressed | 408 | Cholecalciferol (D3), 71 µg | 17 weeks |
| Choukri 2018RCT, placebo | Healthy young women | 152 | Cholecalciferol (D3), 42 µg | 26 weeks |
| Zhang 2018RCT, placebo | Tuberculosis patients with major depression | 123 | Cholecalciferol (D3), 357 µg | 8 weeks |
| Westerberg 2018RCT, placebo | Adults with chronic kidney disease stages 3-4 | 95 | Cholecalciferol (D3), 200 µg | 12 weeks |
| Majid 2018RCT, placebo | Adults aged 20-50 with sleep disorders | 89 | Not named, 89 µg | 8 weeks |
| Bislev 2018RCT, placebo | Postmenopausal women, low vitamin D, high PTH | 81 | Cholecalciferol (D3), 70 µg | 13 weeks |
| Mirzaei 2018RCT, placebo | Fibromyalgia patients with low vitamin D (trazodone in both arms) | 74 | Cholecalciferol (D3), 179 µg | 8 weeks |
| Mousa 2018RCT, placebo | Overweight or obese adults with low vitamin D, no depression | 63 | Cholecalciferol (D3), 100 µg | 16 weeks |
| Mohammadpour 2018RCT, placebo | Children with ADHD on methylphenidate | 62 | Not named, 50 µg | 8 weeks |
| Soubrier 2018RCT, placebo | Rheumatoid arthritis patients with low vitamin D | 59 | Cholecalciferol (D3) | 26 weeks |
| SanMartin 2018Single-arm or open-label | Mild cognitive impairment and early Alzheimer's patients | 52 | Not named | 26 weeks |
| Hiller 2018RCT, placebo | Adults with Parkinson's disease (calcium in both arms) | 51 | Cholecalciferol (D3), 250 µg | 16 weeks |
| Elshorbagy 2018Non-randomised controlled | Children with ADHD and vitamin D deficiency | 50 | Not named | – |
| Krysiak 2018Non-randomised controlled | Young women with low vitamin D | 47 | Not named | 26 weeks |
| Khoja 2018Single-arm or open-label | Adults with rheumatoid arthritis and low vitamin D | 41 | Not named | 39 weeks |
| Rolf 2018RCT, placebo | Women with relapsing-remitting multiple sclerosis | 41 | Cholecalciferol (D3), 100 µg | 16 weeks |
| Krokosz 2018Non-randomised controlled | Male ultramarathon runners | 20 | Cholecalciferol (D3) | – |
| Aucoin 2018RCT, placebo | Adults with non-remitted depression on antidepressants | 9 | Cholecalciferol (D3), 100 µg | 8 weeks |
| Yalamanchili 2018RCT, placebo | Older women with low vitamin D, Black and White | – | Cholecalciferol (D3) | 52 weeks |
| Salas 2018RCT, placebo | Extremely preterm infants followed to 2 years | – | Not named, 20 µg | 4 weeks |
| Hanafy 2018Other | Patients with refractory obesity and fatigue | – | Not named | – |
| Hu 2018RCT, placebo | Not stated (abstract missing) | – | Cholecalciferol (D3) | 52 weeks |
| Khan 2017RCT, placebo | Women with breast cancer on letrozole | 160 | Cholecalciferol (D3), 107 µg | 24 weeks |
| Alam 2017Single-arm or open-label | Adults with painful diabetic neuropathy | 143 | Not named, 15,000 µg | – |
| Han 2017Single-arm or open-label | Kidney transplant recipients | 137 | Cholecalciferol (D3), 20 µg | 26 weeks |
| Saleh 2017RCT, placebo | Adults with fatigue and low vitamin D | 107 | Cholecalciferol (D3), 2,500 µg | – |
| Darwish 2017Single-arm or open-label | Multiple sclerosis patients with low vitamin D | 88 | Cholecalciferol (D3) | 13 weeks |
| Pettersen 2017RCT, active or other control | Healthy adults, northern Canada | 82 | Cholecalciferol (D3), 100 µg | 18 weeks |
| Manios 2017RCT, active or other control | Postmenopausal women in winter | 79 | Cholecalciferol (D3), 6 µg | 8 weeks |
| Dogru 2017Single-arm or open-label | Adults with fibromyalgia and low vitamin D | 70 | Not named | – |
| Ghaderi 2017RCT, placebo | Methadone maintenance patients | 68 | Not named, 89 µg | 12 weeks |
| Grung 2017RCT, placebo | Norwegian adolescents in winter | 50 | Not named | – |
| Penckofer 2017Single-arm or open-label | Women with type 2 diabetes and depressive symptoms | 50 | Ergocalciferol (D2), 179 µg | 26 weeks |
| Krivoy 2017RCT, placebo | Clozapine-treated chronic schizophrenia patients with low vitamin D | 47 | Not named, 50 µg | 8 weeks |
| Rolf 2017RCT, placebo | Adults with relapsing remitting multiple sclerosis | 40 | Cholecalciferol (D3), 350 µg | 48 weeks |
| Narula 2017RCT, active or other control | Adults with Crohn's disease in remission | 34 | Cholecalciferol (D3), 250 µg | 52 weeks |
| Marsh 2017RCT, placebo | Adults with bipolar depression and vitamin D deficiency | 33 | Cholecalciferol (D3), 125 µg | 12 weeks |
| Bostock 2017RCT, placebo | Healthy adults, arm immobilisation | 24 | Not named, 25 µg | 2 weeks |
| Kerley 2017RCT, placebo | Adults with obstructive sleep apnea | 19 | Cholecalciferol (D3), 100 µg | 15 weeks |
| Wang 2016RCT, placebo | Dialysis patients with depression | 746 | Cholecalciferol (D3), 179 µg | 52 weeks |
| Patil 2016RCT, placebo | Older community-dwelling women | 409 | Not named, 20 µg | 104 weeks |
| Westra 2016RCT, placebo | Adults with type 2 diabetes, not deficient | 275 | Cholecalciferol (D3), 42 µg | 26 weeks |
| Vaziri 2016RCT, placebo | Pregnant women without depression | 169 | Cholecalciferol (D3), 50 µg | 12 weeks |
| Tartagni 2016RCT, placebo | Girls with premenstrual mood disorders, low vitamin D | 158 | Not named, 45 µg | 17 weeks |
| Manzo 2016Single-arm or open-label | Older adults with low vitamin D | 132 | Not named | 26 weeks |
| Nowak 2016RCT, placebo | Adults with fatigue and low vitamin D | 120 | Cholecalciferol (D3), 2,500 µg | – |
| Saad 2016Single-arm or open-label | Children with autism and low vitamin D | 106 | Cholecalciferol (D3) | 13 weeks |
| Hoffer 2016Single-arm or open-label | Outpatients with advanced lung cancer | 91 | Not named, 500 µg | 3 weeks |
| Stokes 2016Single-arm or open-label | Chronic liver disease patients with low vitamin D | 77 | Not named, 71 µg | 26 weeks |
| Yilmaz 2016Single-arm or open-label | Adults with chronic widespread pain and low vitamin D | 58 | Cholecalciferol (D3), 179 µg | 13 weeks |
| Lima 2016RCT, placebo | Juvenile-onset lupus patients | 40 | Cholecalciferol (D3), 179 µg | 24 weeks |
| Blagojevic 2016Single-arm or open-label | Children with bone and joint pain and low vitamin D | 35 | Not named | 26 weeks |
| Miller 2016RCT, placebo | Older adults with low vitamin D | 24 | Not named, 179 µg | 8 weeks |
| Al-Dujaili 2016RCT, placebo | Healthy adults | 15 | Cholecalciferol (D3), 50 µg | 2 weeks |
| Mason 2016RCT, placebo | Overweight postmenopausal women with low vitamin D | – | Cholecalciferol (D3), 50 µg | 52 weeks |
| Bergman 2015RCT, placebo | Patients with frequent respiratory infections | 124 | Not named, 100 µg | 52 weeks |
| Gangwar 2015Non-randomised controlled | Elderly adults with dementia and low vitamin D | 80 | Not named | 26 weeks |
| Witham 2015RCT, placebo | Chronic fatigue syndrome patients | 50 | Cholecalciferol (D3), 41 µg | 26 weeks |
| Rolighed 2015RCT, placebo | Primary hyperparathyroidism patients | 46 | Cholecalciferol (D3), 70 µg | 52 weeks |
| Kidir 2015Single-arm or open-label | Dialysis patients with low vitamin D | 37 | Cholecalciferol (D3), 179 µg | 26 weeks |
| Sikoglu 2015Single-arm or open-label | Youth with bipolar spectrum disorders | 35 | Cholecalciferol (D3), 50 µg | 8 weeks |
| Tazzyman 2015RCT, placebo | Adults with irritable bowel syndrome | – | Not named | – |
| Slow 2014RCT, placebo | Healthy adults exposed to earthquakes | 322 | Cholecalciferol (D3), 82 µg | 78 weeks |
| Ramly 2014RCT, placebo | Vitamin D deficient premenopausal women | 192 | Not named, 62 µg | 52 weeks |
| Roy 2014Single-arm or open-label | Fatigued primary care patients with low vitamin D | 174 | Ergocalciferol (D2) | 5 weeks |
| Nadkarni 2014Single-arm or open-label | Treatment-resistant depression, outpatients with vitamin D deficiency | 62 | Not named | – |
| Rorie 2014RCT, active or other control | Chronic urticaria patients | 42 | Cholecalciferol (D3), 100 µg | 12 weeks |
| Frandsen 2014RCT, placebo | Healthcare professionals with seasonal affective symptoms | 34 | Not named, 70 µg | 12 weeks |
| Wepner 2014RCT, placebo | Women with fibromyalgia | 30 | Cholecalciferol (D3) | 20 weeks |
| Mozaffari-Khosravi 2013RCT, active or other control | Depressed adults with vitamin D deficiency | 120 | Not named, 7,500 µg | – |
| Le Goaziou 2013Single-arm or open-label | Adults with musculoskeletal pain and vitamin D deficiency | 49 | Not named | – |
| Khoraminya 2013RCT, placebo | Adults with major depression on fluoxetine | 42 | Cholecalciferol (D3), 38 µg | 8 weeks |
| Huang 2013Single-arm or open-label | Veterans with chronic pain and low vitamin D | 28 | Not named | – |
| Sinha 2013Single-arm or open-label | Symptomatic vitamin D deficient adults | 12 | Cholecalciferol (D3) | – |
| Gominak 2012Single-arm or open-label | Patients with neurologic complaints and abnormal sleep | 1,500 | Not named | 104 weeks |
| Kjærgaard 2012RCT, placebo | Adults with low serum vitamin D | 230 | Cholecalciferol (D3), 143 µg | 26 weeks |
| Kampman 2012RCT, placebo | Adults with multiple sclerosis | 68 | Cholecalciferol (D3), 71 µg | 96 weeks |
| Högberg 2012Single-arm or open-label | Depressed adolescents with vitamin D deficiency | 48 | Cholecalciferol (D3) | 13 weeks |
| Annweiler 2012Non-randomised controlled | Alzheimer patients | 43 | Not named | 26 weeks |
| Askmark 2012Single-arm or open-label | Myasthenia gravis patients | 13 | Cholecalciferol (D3), 20 µg | 26 weeks |
| Annweiler 2012Single-arm or open-label | Older memory clinic outpatients | – | Not named | – |
| Dean 2011RCT, placebo | Healthy young adults | 128 | Cholecalciferol (D3), 125 µg | 6 weeks |
| Stein 2011RCT, placebo | Mild-moderate Alzheimer patients | 32 | Ergocalciferol (D2) | 8 weeks |
| Zwart 2011Non-randomised controlled | Antarctic winter workers | 29 | Not named, 50 µg | 26 weeks |
| Sanders 2011RCT, placebo | Community-dwelling older women | – | Cholecalciferol (D3), 34 µg | – |
| Burback 2011Other | Older women | – | Not named | – |
| Khan 2010Single-arm or open-label | Women starting letrozole for breast cancer | 60 | Cholecalciferol (D3), 179 µg | 12 weeks |
| Arvold 2009RCT, placebo | Primary care adults with vitamin D deficiency | 100 | Cholecalciferol (D3), 179 µg | 8 weeks |
| Shipowick 2009Single-arm or open-label | Women with low vitamin D in winter | 9 | Cholecalciferol (D3) | – |
| Jorde 2008RCT, placebo | Overweight and obese adults | 441 | Cholecalciferol (D3), 143 µg | 52 weeks |
| Björkman 2008RCT, placebo | Bedridden aged dementia patients in pain | 202 | Cholecalciferol (D3), 30 µg | 26 weeks |
| Przybelski 2008Non-randomised controlled | Nursing home residents with low vitamin D | 63 | Ergocalciferol (D2), 536 µg | 4 weeks |
| Shah 2005Single-arm or open-label | Peritoneal dialysis patients with vitamin D deficiency | 29 | Ergocalciferol (D2), 179 µg | 4 weeks |
| Vieth 2004RCT, active or other control | Outpatients with low vitamin D status | 130 | Cholecalciferol (D3), 100 µg | 26 weeks |
| Gloth 1999RCT, active or other control | Adults with seasonal affective disorder | 15 | Not named, 2,500 µg | – |
| Lansdowne 1998RCT, placebo | Healthy adults in late winter | 44 | Cholecalciferol (D3), 20 µg | 1 weeks |
| Harris 1993RCT, placebo | Women aged 43 to 72, Boston area | 250 | Not named, 10 µg | 52 weeks |
| Bech 1979Observational | Obese patients after intestinal bypass | 43 | Cholecalciferol (D3) | – |
| Røodbro 1975Non-randomised controlled | Epilepsy outpatients on anticonvulsants | 226 | Not named, 50 µg | 13 weeks |
| BONELLI 1952Other | Manic-depressive psychosis patients | – | Ergocalciferol (D2) | – |
Safety
What's known about safety
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In trials
This page doesn't yet summarise side effects reported in trials. The NHS says that taking too much vitamin D over time can cause too much calcium to build up in the body (hypercalcaemia), which can weaken the bones and damage the kidneys and the heart.
NHS, Vitamin D, Oct 2026
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In the UK
Vitamin D is on the permitted vitamins list for food supplements. The NHS says not to take more than 100 micrograms (4,000 IU) a day, as it could be harmful. Government advice is that everyone should consider taking a daily vitamin D supplement during the autumn and winter, and the NHS says adults and children over 4 should consider one containing 10 micrograms.
NHS, Vitamin D; retained Directive 2002/46/EC Annex I (legislation.gov.uk), Oct 2026
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Check first
The NHS says some people have medical conditions that mean they may not be able to safely take as much, and that if in doubt you should speak to your doctor. If a doctor has recommended a different amount, follow their advice.
NHS, Vitamin D, Oct 2026
How we built this
Where these studies come from
We list every published study of vitamin D in people that measured thinking, memory, mood, stress, sleep, energy, tiredness or quality of life. The vitamin must be given to people as D3, D2 or calcifediol, daily, weekly, monthly or as a single large dose. Active vitamin D drugs (calcitriol, alfacalcidol, paricalcitol), sunlight, UV lamps and light therapy are left out, and studies that only measure blood levels are left out. Vitamin D with calcium counts as a blend. This first version is built from each study's summary; full-paper checks come next.
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We search
PubMed, the world's main library of medical research, for every paper on L-theanine.
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We keep studies in people
Lab and animal work is counted but left out of the list, because it doesn't tell you what happens in people.
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We note the basics
Who took part, how many, how much and for how long, from each study's published summary. A second check corrects what the first read gets wrong.
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We read them in full
Results appear once we've read the whole paper and checked every number. The date at the top shows when this entry was last updated.
Download the study list
Every study in people as a spreadsheet, 262 rows, free to reuse with a link back.
Versions
Each update to the data gets a new version number, so you can tell what changed and when.
See every version
1.0 · 24 Oct 2026. First release. Every published study giving vitamin D to people that measured thinking, memory, mood, stress, sleep, energy or quality of life is listed from its summary. None is read in full yet.
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