Calcium and vitamin d3 supplementation
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Calcium and Vitamin D3 Supplementation: Effects on Bone Health and Fracture Risk
Research consistently shows that combined calcium and vitamin D3 supplementation helps reduce the risk of hip and non-vertebral fractures in older adults, especially in elderly women. Multiple large randomized controlled trials and meta-analyses have found that daily supplementation with 800 IU of vitamin D3 and 1200 mg of calcium significantly lowers the incidence of hip fractures and other non-vertebral fractures compared to placebo, with odds ratios indicating a 25% reduction in hip fracture risk and a 20% reduction in non-vertebral fracture risk 45910. These benefits are most pronounced in institutionalized or community-dwelling elderly women, where supplementation also reverses secondary hyperparathyroidism and helps maintain bone mineral density at the femoral neck 4910.
Impact on Parathyroid Hormone and Bone Markers
Supplementation with both calcium and vitamin D3, rather than either alone, leads to a significant decrease in parathyroid hormone (PTH) levels and an increase in calcium/creatinine ratio, indicating improved calcium metabolism and bone health 149. These changes are associated with a reduction in bone turnover and a stabilization or increase in bone mineral density, particularly in the hip region 49.
Effects on Muscle Function and Physical Performance
In older adults, supplementation with vitamin D3 and calcium (sometimes combined with other nutrients like HMB) has been shown to improve muscle strength, lean body mass, and physical functionality, even in those not participating in exercise programs . This suggests that supplementation may help reduce the risk of falls and related injuries in the elderly .
Cancer and Cardiovascular Disease Outcomes
Long-term studies indicate that calcium and vitamin D3 supplementation may reduce cancer mortality by about 7% in postmenopausal women, and some trials have shown a reduction in overall cancer risk with supplementation 378. However, there is also evidence of a slight increase (about 6%) in cardiovascular disease mortality with long-term supplementation, and no effect on all-cause mortality 37. The impact on cancer incidence appears to be more significant when supplementation is started in individuals with low baseline vitamin D levels .
Effects on Body Composition and Metabolic Health
In overweight and obese adults with very low calcium intake, calcium plus vitamin D3 supplementation during calorie restriction leads to greater reductions in body fat and visceral fat compared to calorie restriction alone, although there is no significant difference in overall body weight or metabolic variables .
Cost-Effectiveness of Supplementation
Supplementing institutionalized elderly women with calcium and vitamin D3 is cost-effective for hip fracture prevention, resulting in substantial healthcare savings by reducing the number of fractures and associated treatment costs .
Conclusion
Calcium and vitamin D3 supplementation is effective in reducing fracture risk, improving bone health, and supporting muscle function in older adults, particularly women. There is also evidence for reduced cancer risk, though potential cardiovascular risks should be considered. Supplementation is most beneficial in populations at risk for deficiency and is a cost-effective strategy for fracture prevention in the elderly.
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