Calcium vitamin d side effects
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Side Effects of Calcium and Vitamin D Supplementation
Hypercalcemia and Hypercalciuria Risks
Long-term supplementation with vitamin D has been associated with increased risks of hypercalcemia and hypercalciuria. A systematic review and meta-analysis of 48 studies involving 19,833 participants found that vitamin D supplementation significantly increased the risk of hypercalcemia (Relative Risk [RR]: 1.54) and hypercalciuria (RR: 1.64) . These risks were not influenced by the baseline levels of 25-hydroxyvitamin D, the dose and duration of vitamin D supplementation, or whether calcium was co-supplemented .
Kidney Stones
Contrary to concerns, vitamin D supplementation did not significantly increase the risk of kidney stones. In the same meta-analysis, kidney stones were reported in only 9 trials, with a tendency for fewer subjects reporting stones in the vitamin D group compared to the placebo group (RR: 0.66) . This suggests that while hypercalcemia and hypercalciuria are risks, kidney stones may not be a significant concern with vitamin D supplementation alone.
Cardiovascular Events
Calcium supplements, with or without vitamin D, have been linked to an increased risk of cardiovascular events. A reanalysis of the Women's Health Initiative (WHI) Calcium/Vitamin D Supplementation Study and a meta-analysis of eight other studies found that calcium and vitamin D supplementation increased the risk of myocardial infarction (RR: 1.24) and the composite of myocardial infarction or stroke (RR: 1.15) . This finding suggests a need for caution when considering calcium and vitamin D supplementation, particularly in individuals with existing cardiovascular risk factors.
Effects on Glucose Metabolism and Lipid Concentrations
In overweight and obese women with polycystic ovary syndrome (PCOS), calcium plus vitamin D supplementation showed beneficial effects on glucose metabolism and lipid concentrations. The supplementation led to decreased serum insulin levels, improved insulin sensitivity, and reduced serum triglycerides and VLDL-cholesterol levels . However, these benefits were specific to this population and may not be generalizable to all individuals.
Skeletal Health and Fracture Prevention
The combination of calcium and vitamin D has been shown to reduce the risk of osteoporotic fractures. A systematic review and meta-analysis indicated that this combination reduced total fractures and hip fractures, although it had no effect on wrist fractures . Additionally, a five-year randomized controlled trial in elderly women found that calcium plus vitamin D supplementation preserved hip bone mineral density and reduced bone turnover rates .
Conclusion
While calcium and vitamin D supplementation can offer benefits such as improved bone health and metabolic outcomes in specific populations, they also carry risks, particularly of hypercalcemia, hypercalciuria, and cardiovascular events. These risks highlight the importance of personalized medical advice and careful consideration of individual health profiles before starting supplementation. Further large-scale randomized controlled trials are needed to confirm these findings and provide clearer guidelines.
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