Vitamin d supplementation without calcium
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Vitamin D Supplementation Without Calcium: Effects on Calcium Absorption
Vitamin D supplementation alone has been shown to increase calcium absorption in the body. In a study of healthy postmenopausal women, increasing doses of vitamin D led to a significant, linear increase in calcium absorption, with no evidence of a threshold effect. This means that higher vitamin D levels continued to improve calcium absorption, even without additional calcium supplementation, within the studied range .
Vitamin D Alone and Skeletal Health Outcomes
When it comes to preventing fractures, the evidence suggests that vitamin D supplementation by itself does not significantly reduce the risk of fractures, including hip fractures, in community-dwelling adults. Multiple large-scale analyses and meta-analyses have found that vitamin D alone does not lower the risk of total or hip fractures, while the combination of vitamin D and calcium does show a modest benefit in reducing hip fracture risk, especially in institutionalized individuals or those at high risk of deficiency 245.
Vitamin D Supplementation and Fall Prevention
Vitamin D supplementation at daily doses of 800–1000 IU has been associated with a lower risk of falls among older adults, regardless of whether calcium is also supplemented. This benefit is most pronounced in individuals with vitamin D deficiency and when vitamin D is taken daily rather than intermittently. High doses of vitamin D above 1000 IU per day may actually increase the risk of falls 34.
Vitamin D Supplementation and Cardiovascular Health
Randomized controlled trials have not found any cardiovascular benefit from vitamin D supplementation alone. The evidence suggests that vitamin D supplements are generally safe for cardiovascular health, with no increased risk of cardiovascular events. However, calcium supplementation (with or without vitamin D) has been linked in some studies to a modest increase in cardiovascular risk, particularly myocardial infarction, so obtaining calcium from dietary sources is preferred 67910.
Vitamin D Supplementation in Pregnancy
Vitamin D supplementation during pregnancy, with or without calcium, may help reduce the risk of preeclampsia. Some studies suggest that vitamin D alone can lower this risk, but more large-scale trials are needed to confirm these findings .
Conclusion
Vitamin D supplementation without calcium increases calcium absorption and may help reduce the risk of falls, especially in older adults with vitamin D deficiency. However, vitamin D alone does not significantly reduce fracture risk or provide cardiovascular benefits. For fracture prevention, the combination of vitamin D and calcium is more effective, particularly in high-risk groups. Vitamin D supplementation is generally safe, but calcium supplements should be used cautiously, with a preference for dietary sources.
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