Mineola, New York: Even recommended intake of Vitamin D with calcium supplements may increase kidney stone risk. Frequent hypercalciuria can result when the safe upper level of vitamin D recommended by the Endocrine Society is co-administered with calcium supplements, is the finding of a randomized controlled trial.
The study, published in the journal Clinical Endocrinology, suggests that the risk of kidney stones at these levels should be investigated.
John F. Aloia, Winthrop University Hospital, Bone Mineral Research Center, Mineola, New York, and colleagues conducted the study to compare the episodes of hypercalciuria and hypercalcaemia from calcium supplements co‐administered with 10 000 IU or 600 IU (intake of vitamin D found acceptable by Endocrine Society Guidelines) vitamin D daily in white postmenopausal women.
The 66 participants (average age, 61.5) in the first group were administered 1200 mg/day of calcium carbonate plus 10,000 IU/day of vitamin D3 and 66 participants in the second group received 1200 mg/day of calcium carbonate plus 400 IU/day of vitamin D3.
Over 1 year, participants were evaluated every 3 months for the development of hypercalcemia and hypercalciuria. Baseline characteristics were similar in both groups.
- Of the 47 individuals in the high-dose vitamin D group who completed the trial, 34 developed hypercalciuria at least once, 15 participants developed the condition 2 to 3 times, and 5 were hypercalciuric 4 times.
- Of the 45 individuals in the low vitamin D group who completed the trial, 19 developed hypercalciuria at least once, 7 developed hypercalciuria 2 to 3 times, and 2 were hypercalciuric 4 times.
- Via mixed-effects logistic regression modelling, the researchers determined that the odds of developing hypercalciuria over time were 3.6 times greater in the high-dose vitamin D group than the low-dose vitamin D group.
- As for hypercalcemia, 23% of participants in the high-dose group developed the condition at least once compared with 17% in the low-dose group.
- There was not a significant time and group interaction term, indicating that the odds of developing hypercalcemia were no greater in the high-dose group than the low-dose group.
Until further large scale studies are performed the upper limit for vitamin D proposed by the Institute of Medicine is to be preferred to that proposed by the Endocrine Society,” concluded the researchers, adding, “The upper limit for calcium intake should also be reexamined.”
For further reference log on to https://doi.org/10.1111/cen.13848