Does vitamin D prevent fractures?

No. In healthy adults living at home, vitamin D alone did not lower the chance of a broken bone, even at 2,000 IU a day.

Who it's for

Not shown to help healthy adults; benefit is unproven for frail older people.

What to expect

No clear drop in fractures from vitamin D alone.

Watch out for

Calcium plus vitamin D raised kidney stone risk in one large trial.

What guidelines say

The US Preventive Services Task Force recommends against daily vitamin D (400 IU or less) with calcium (1,000 mg or less) to prevent fractures in postmenopausal women living at home1Guideline · 2018Vitamin D, Calcium, or Combined Supplementation for the Primary Prevention of Fractures in Community-Dwelling AdultsThe USPSTF concludes that the current evidence is insufficient to assess the balance of the benefits and harms of vitamin D and calcium supplementation, alone or combined, for the primary prevention of fractures in men and premenopausal women. (I statement)US Preventive Services Task Force. It calls the evidence insufficient for men and premenopausal women1Guideline · 2018Vitamin D, Calcium, or Combined Supplementation for the Primary Prevention of Fractures in Community-Dwelling AdultsThe USPSTF concludes that the current evidence is insufficient to assess the balance of the benefits and harms of vitamin D and calcium supplementation, alone or combined, for the primary prevention of fractures in men and premenopausal women. (I statement)US Preventive Services Task Force. The Endocrine Society suggests routine vitamin D for children, pregnant women, adults with high-risk prediabetes and adults 75 and older, but not for healthy adults 19 to 742Guideline · 2026Vitamin D: Fact Sheet for Health ProfessionalsThe Endocrine Society recommends routine vitamin D supplementation for children and teens age 1 to 18 years, pregnant women, adults with pre-diabetes, and adults age 75 years and older, but not for healthy adults age 19 to 74.NIH Office of Dietary Supplements,9Guideline · 2024Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline.The panel suggests empiric vitamin D for those aged 1 to 18 years and adults over 75 years of age, those who are pregnant, and those with high-risk prediabetes. Due to the scarcity of natural food sources rich in vitamin D, empiric supplementation can be achieved through a combination of fortified foods and…J Clin Endocrinol Metab.

What the studies show

• The newest and largest review pooled 69 trials with 153,902 people, mostly living at home and not at high risk. Vitamin D alone had no effect on any fracture (36 trials, 92,045 people), rated high certainty8Meta-analysis · 2026 · 9,067 peopleCalcium, vitamin D, or combined supplementation to prevent fractures and falls: systematic review and meta-analysis.Based on absolute risk reductions and thresholds considered clinically meaningful, this review found little to no benefits from use of calcium, vitamin D, or combined supplementation on the prevention of fractures and falls.BMJ.
• In the same review, vitamin D plus calcium gave a small drop in any fracture, about 9% fewer than placeboplacebo A dummy treatment that looks like the real one, so people can't tell which they got. or no treatment, also rated high certainty. The review judged this too small to matter for most people8Meta-analysis · 2026 · 9,067 peopleCalcium, vitamin D, or combined supplementation to prevent fractures and falls: systematic review and meta-analysis.Based on absolute risk reductions and thresholds considered clinically meaningful, this review found little to no benefits from use of calcium, vitamin D, or combined supplementation on the prevention of fractures and falls.BMJ. Figures like these compare groups, so the gain for one person depends on their starting risk.
• A trial of 25,871 US adults (men 50 and older, women 55 and older) gave 2,000 IU a day or a dummy pill (placebo) for a median of 5.3 years. Total, hip and other non-spine fractures were no less common with vitamin D5Randomized trial · 2022 · 25,871 peopleSupplemental Vitamin D and Incident Fractures in Midlife and Older Adults.Vitamin D3 supplementation did not result in a significantly lower risk of fractures than placebo among generally healthy midlife and older adults who were not selected for vitamin D deficiency, low bone mass, or osteoporosis. (Funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases; VITAL…N Engl J Med.
• A trial of 2,157 adults aged 70 and older found no effect of 2,000 IU a day on non-spine fractures over 3 years7Randomized trial · 2020 · 2,157 peopleEffect of Vitamin D Supplementation, Omega-3 Fatty Acid Supplementation, or a Strength-Training Exercise Program on Clinical Outcomes in Older Adults: The DO-HEALTH Randomized Clinical Trial.Among adults without major comorbidities aged 70 years or older, treatment with vitamin D3, omega-3s, or a strength-training exercise program did not result in statistically significant differences in improvement in systolic or diastolic blood pressure, nonvertebral fractures, physical performance, infection rates, or…JAMA.
• Older reviews found benefit mainly at higher doses. One pooled 11 trials in people 65 and older, mostly women. Those taking about 800 IU or more a day had 30% fewer hip fractures than controls10Meta-analysis · 2012 · 31,022 peopleA pooled analysis of vitamin D dose requirements for fracture prevention.High-dose vitamin D supplementation (≥800 IU daily) was somewhat favorable in the prevention of hip fracture and any nonvertebral fracture in persons 65 years of age or older. (Funded by the Swiss National Foundations and others.).N Engl J Med. Another found 700 to 800 IU a day linked to 26% fewer hip fractures, but 400 IU did nothing3Meta-analysis · 2005 · 9,820 peopleFracture prevention with vitamin D supplementation: a meta-analysis of randomized controlled trials.Oral vitamin D supplementation between 700 to 800 IU/d appears to reduce the risk of hip and any nonvertebral fractures in ambulatory or institutionalized elderly persons. An oral vitamin D dose of 400 IU/d is not sufficient for fracture prevention.JAMA. These older findings were not confirmed by the larger, newer trials5Randomized trial · 2022 · 25,871 peopleSupplemental Vitamin D and Incident Fractures in Midlife and Older Adults.Vitamin D3 supplementation did not result in a significantly lower risk of fractures than placebo among generally healthy midlife and older adults who were not selected for vitamin D deficiency, low bone mass, or osteoporosis. (Funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases; VITAL…N Engl J Med,8Meta-analysis · 2026 · 9,067 peopleCalcium, vitamin D, or combined supplementation to prevent fractures and falls: systematic review and meta-analysis.Based on absolute risk reductions and thresholds considered clinically meaningful, this review found little to no benefits from use of calcium, vitamin D, or combined supplementation on the prevention of fractures and falls.BMJ.
• A 1997 trial of 389 older adults found fewer non-spine fractures with 500 mg calcium plus 700 IU vitamin D over three years. It was small, and the result was not repeated in later, larger trials12Randomized trial · 1997 · 213 peopleEffect of calcium and vitamin D supplementation on bone density in men and women 65 years of age or older.In men and women 65 years of age or older who are living in the community, dietary supplementation with calcium and vitamin D moderately reduced bone loss measured in the femoral neck, spine, and total body over the three-year study period and reduced the incidence of nonvertebral fractures.N Engl J Med.

Key studies

Safety

In the large women's trial, calcium plus 400 IU vitamin D raised kidney stone risk by 17% relative to placebo11Randomized trial · 2006 · 36,282 peopleCalcium plus vitamin D supplementation and the risk of fractures.Among healthy postmenopausal women, calcium with vitamin D supplementation resulted in a small but significant improvement in hip bone density, did not significantly reduce hip fracture, and increased the risk of kidney stones. (ClinicalTrials.gov number, NCT00000611.).N Engl J Med. The 2,000 IU trial found no major differences in side effects between groups5Randomized trial · 2022 · 25,871 peopleSupplemental Vitamin D and Incident Fractures in Midlife and Older Adults.Vitamin D3 supplementation did not result in a significantly lower risk of fractures than placebo among generally healthy midlife and older adults who were not selected for vitamin D deficiency, low bone mass, or osteoporosis. (Funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases; VITAL…N Engl J Med. The upper intake limit ranges from 1,000 to 4,000 IU a day depending on age2Guideline · 2026Vitamin D: Fact Sheet for Health ProfessionalsThe Endocrine Society recommends routine vitamin D supplementation for children and teens age 1 to 18 years, pregnant women, adults with pre-diabetes, and adults age 75 years and older, but not for healthy adults age 19 to 74.NIH Office of Dietary Supplements.

What we don't know

• Whether vitamin D helps people who are truly deficient, in nursing homes, or at very high fracture risk. The evidence for these groups is limited8Meta-analysis · 2026 · 9,067 peopleCalcium, vitamin D, or combined supplementation to prevent fractures and falls: systematic review and meta-analysis.Based on absolute risk reductions and thresholds considered clinically meaningful, this review found little to no benefits from use of calcium, vitamin D, or combined supplementation on the prevention of fractures and falls.BMJ.
• Whether high daily doses help some older people, since older and newer reviews disagree.