Vitamin D and Healthy Aging: Trial Evidence
What large randomized trials of vitamin D show for cancer, heart disease, fractures and death in older adults, and why the answer differs for people who are low in vitamin D.
Content last updated . This page has not been medically reviewed.
What the big trials found
| Trial or review | Who and how long | Main result |
|---|---|---|
| VITAL | 25,871 US adults (men 50+, women 55+), median 5.3 years | No lower risk of cancer (hazard ratio 0.96) or major cardiovascular events (0.97); death from any cause 0.99 [1] |
| VITAL fracture study | The same 25,871 people | No significant effect on total fractures (0.98) or hip fractures (1.01) [2] |
| D-Health | 21,315 Australians aged 60 and older, 5 years | No reduction in all-cause death (hazard ratio 1.04) [3] |
| Cochrane review of mortality | 56 trials, 95,286 people | See below [4] |
| Cochrane review of cancer | 18 trials, 50,623 people | Cancer occurrence unchanged (risk ratio 1.00) [5] |
The amounts in these trials were study amounts, not advice: VITAL used 2,000 IU of vitamin D3 a day, and D-Health used 60,000 IU once a month. [1][3]
How to read vitamin D longevity claims
- Ask whether the study picked people who were low in vitamin D.
- Ask whether the outcome was death or disease, or only a blood level.
- Be cautious of products that claim to "slow aging" with vitamin D. The FDA says supplement claims of this kind are not pre-approved. [6]
For the wider picture, see Supplements for healthy aging, Longevity interventions: what human evidence exists and How we label evidence in longevity research.
Frequently asked questions
Does vitamin D help you live longer?
In the large trials of generally healthy older adults, no clear reduction in death was seen. D-Health found a hazard ratio of 1.04 for all-cause death and VITAL found 0.99. [3][1] An older Cochrane review suggested a small benefit for vitamin D3 in elderly people, with important weaknesses. [4]
Does vitamin D prevent cancer or heart disease?
In VITAL, vitamin D did not lower the risk of invasive cancer or major cardiovascular events compared with placebo. [1] A Cochrane review of 18 trials found no change in cancer occurrence. [5]
Does vitamin D prevent fractures?
In the VITAL fracture study, vitamin D3 did not significantly lower fractures among people not selected for deficiency, low bone mass or osteoporosis. [2] This does not address people with diagnosed deficiency or bone disease, who should follow their clinician's advice.
Should older adults take vitamin D?
That is a decision for the person and their clinician, based on diet, sun exposure, blood tests and health conditions. This page does not recommend starting or stopping a supplement. NIA advises talking with your doctor before taking a supplement. [7]
Is "anti-aging vitamin D" a proven claim?
No. The trials above did not test whether vitamin D slows aging, and no source we read shows that it does. Label: marketing claim.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
How to read the evidence labels
Labels used on this page: established, promising but limited, mixed, insufficient evidence, no good evidence of benefit and evidence of harm.
Across the large trials below, vitamin D given to generally healthy older adults did not clearly lower cancer, heart events, fractures or death. Some older reviews pointed toward a small survival benefit, so the overall picture is mixed, leaning toward no good evidence of benefit for people who are not deficient.
Why results seem to disagree
Many earlier trials enrolled older women in care settings, who are more likely to be short of vitamin D. Benefit from fixing a shortage does not mean benefit from adding more when levels are already adequate.
Safety and limits
- VITAL found no excess of high blood calcium or other adverse events at its study amount. [1]
- In the Cochrane review, vitamin D3 combined with calcium increased kidney stones. [4]
- In D-Health, deaths from cancer were not significantly different overall (hazard ratio 1.15, 95% CI 0.96 to 1.39), but an exploratory analysis excluding the first two years pointed toward a higher cancer-death risk. The authors suggested caution about high monthly doses in people whose levels were already adequate. These are exploratory findings, not proof of harm. [3]
- Vitamin D blood levels (a biomarker) are not the same as health outcomes.
Who should check first
References
- Manson JE et al., N Engl J Med 2019. Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease (VITAL). Read 2026-10-22.
- LeBoff MS et al., N Engl J Med 2022. Supplemental Vitamin D and Incident Fractures in Midlife and Older Adults. Read 2026-10-22.
- Neale RE et al., Lancet Diabetes Endocrinol 2022. The D-Health Trial: a randomised controlled trial of the effect of vitamin D on mortality. Read 2026-10-22.
- Bjelakovic G et al., Cochrane Database Syst Rev 2014. Vitamin D supplementation for prevention of mortality in adults. Read 2026-10-22.
- Bjelakovic G et al., Cochrane Database Syst Rev 2014. Vitamin D supplementation for prevention of cancer in adults. Read 2026-10-22.
- U.S. Food and Drug Administration, Label Claims for Conventional Foods and Dietary Supplements. Page content current as of 03/28/2024. Read 2026-10-22.
- National Institute on Aging, Dietary Supplements for Older Adults. Read 2026-10-22.