Vitamin D3: what the studies show, and the products
210 of the human studies we graded used vitamin D3, and 52 showed an improvement. Its products are graded on the studies of every form of vitamin d. This page is educational, not medical advice.
What it does, by goalMembersThe top 5 of 18 goals
6 of these 180 human studies gave vitamin D3 by drip or injection, not by mouth.
| Goal | What the studies show | Studies | Dose that worked |
|---|---|---|---|
| Improved in studies 18 studies, 8 showed an improvement, 5 found none, 1 pooled analysis | 18 | 600 IU | |
| Improved in studies 10 studies, 6 showed an improvement, 2 found none | 10 | 0.3 mcg | |
| Improved in studies 28 studies, 5 showed an improvement, 11 found none, 2 pooled analyses | 28 | 10,000 IU | |
| Improved in studies 26 studies, 5 showed an improvement, 14 found none, 2 pooled analyses, 1 by drip, injection or inhaler | 26 | 1,200 IU | |
| Improved in studies 15 studies, 5 showed an improvement, 6 found none, 2 pooled analyses, 1 by drip, injection or inhaler | 15 | 100 IU | |
| Improved in studies 10 studies, 4 showed an improvement, 3 found none, 1 pooled analysis | 10 | 1,000 IU | |
| Improved in studies 10 studies, 4 showed an improvement, 1 found none | 10 | 2,000 IU | |
| Improved in studies 9 studies, 3 showed an improvement, 3 found none, 1 pooled analysis | 9 | – | |
| Improved in studies 8 studies, 3 showed an improvement, 1 found none, 1 pooled analysis, 2 by drip, injection or inhaler | 8 | – | |
| Improved in studies 3 studies, 2 showed an improvement, 1 pooled analysis, 1 by drip, injection or inhaler | 3 | – | |
| Improved in studies 3 studies, 1 showed an improvement, 2 found none | 3 | 1,200 IU | |
| Improved in studies 2 studies, 1 showed an improvement | 2 | 1,600 IU | |
| Too few studies 1 study, no clear result | 1 | – | |
| No effect in studies 10 studies, 4 showed an improvement, 2 found none, 2 pooled analyses | 10 | 2,000 IU | |
| No effect in studies 24 studies, 2 showed an improvement, 15 found none, 2 by drip, injection or inhaler | 24 | 4,000 IU | |
| No effect in studies 6 studies, 2 showed an improvement, 3 found none | 6 | 2,000 IU | |
| No effect in studies 17 studies, 1 showed an improvement, 11 found none | 17 | – | |
| No effect in studies 5 studies, 1 showed an improvement, 1 found none, 3 pooled analyses | 5 | 1,000 IU |
Members see which goal each result is for, and the products for it. Start My 7-Day Free Trial →
Products – highest ranked firstMembersThe top 3 of 27
Members see the products, their ranking and the reasons. Start My 7-Day Free Trial →
Dose and safetyThe dose that worked and the upper limit
The studies of vitamin D3 taken by mouth that showed an improvement gave 100 to 200,000 IU a day.
The upper limit for adults is 100 mcg of vitamin d a day; above it, members see a note and are told they can take less.
Biohacker panelMembersWhat our 10 biohackers say about vitamin D3
Questions people askMembersAnswered from the figures on this page
What is vitamin D3 good for?
Answer for members.
How much vitamin D3 a day?
Answer for members.
Can I take vitamin D3 with my meds?
Answer for members.
Members see the answers, checked against their own meds and goals. Start My 7-Day Free Trial →
Educational, not medical advice. Figures come from the human studies on PubMed we have graded; a study counts for a form when it names the form it used. Updated as new studies arrive. How we grade →