PlainPill

Vitamin D Supplementation

People mainly take Vitamin D Supplementation for energy, focus, immunity. Based on 3 first-hand reports and 1,028 meta-analyses & systematic reviews in the medical literature. Ranked #1301 of 3,539 overall.

22
User score
Mostly positive
67% positive33% mixed0% negative0% unclear

Of reports that state an outcome, 67% are positive.

Clinical research
AStrong research base
1,028
meta-analyses
1,599
RCTs
10,877
papers

What Vitamin D Supplementation does, according to users

Of the people who reported each effect, the share who said it got better.

What the research says

Systematic reviews and meta-analyses from PubMed, with their published conclusions.

AStrong research base

3+ meta-analyses or systematic reviews and 10+ randomized controlled trials in humans. The grade measures how much human research exists — read the conclusions below for what it found.

BMJ · 2019 · Meta-analysis / systematic review
Association between vitamin D supplementation and mortality: systematic review and meta-analysis

Conclusion: Vitamin D supplementation alone was not associated with all cause mortality in adults compared with placebo or no treatment. Vitamin D supplementation reduced the risk of cancer death by 16%. Additional large clinical studies are needed to determine whether vitamin D3 supplementation is associated with lower all cause mortality.

PubMed 31405892 ↗
BMJ · 2017 · Meta-analysis / systematic review
Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data

Conclusion: The body of evidence contributing to these analyses was assessed as being of high quality.Conclusions Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall. Patients who were very vitamin D deficient and those not receiving bolus doses experienced the most benefit.Systematic review registration PROSPERO CRD42014013953.

PubMed 28202713 ↗

Dosage people report

As stated by users — not a recommendation. Follow the label or your doctor.

25-50,000 IUas reported
50000 IUweekly

Reported side effects

How often each side effect came up across all reports.

hypercalcemia ×1falls ×1

What users say

First-hand experiences, quoted verbatim. We show one positive and one negative where both exist.

Other options for energy

User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 3, 2026. How we rate