A new study suggests that hypercalciuria and hypercalcemia, conditions in which calcium levels in the blood and urine are too high, might occur after the use of vitamin D and calcium supplements in older women.
Calcium supplements are widely used to reduce bone resorption in osteoporosis, and many studies support this use. Vitamin D aids in the absorption of calcium. It is used, alone or in combination with calcium, to increase bone mineral density and decrease fractures.
In a recent study, researchers randomly assigned 163 women 57-90 years-old to receive 400-4,800 IU of vitamin D daily plus 200 mg of calcium citrate tablets (to reach a daily calcium intake of about 1,200 mg), to assess how frequently hypercalciuria and hypercalcemia occur in older women talking vitamin D and calcium supplements. At the beginning of the study, all women had low vitamin D levels. Blood and urine levels of calcium were collected every 3 months throughout the study.
The researchers found that following supplementation, hypercalcemia and hypercalciuria occurred in 8.8% and 30.6% of the participating women, respectively. There was no association between the dose of vitamin D and the incidence of these conditions. About half of the cases of hypercalciuria lasted for only a short-time, while the other half were recurring. Additionally, hypercalciuria also occurred in the women talking placebo.
The authors concluded that both hypercalciuria and hypercalcemia might occur with the use of vitamin D and calcium supplements. However, it is unclear if the combination of vitamin D and calcium, or the use of just one of them alone, is the cause. Additionally, the authors noted that these findings may provide some insight into the increase in kidney stones as reported in the Women’s Health Initiative trial. Additional research is needed to further understand these findings.
For more information about calcium or vitamin D, please visit Natural Standard’s Foods, Herbs & Supplements Database.