Follow-up study of biological parameters in elderly institutionalized patients more than one year after discontinuation of calcium-vitamin D supplementation.

Laboratory tests were done 15 to 19 months after completion of a six-month clinical trial of oral supplementation with 1 g elemental calcium and 800 IU vitamin D per day in elderly institutionalized patients. Serum 25-OH-vitamin D and intact parathyroid hormone levels returned to normal during the trial, indicating efficacy of the supplementation in correcting the vitamin D deficiency and secondary hyperparathyroidism present before the trial. Data were available before, during, immediately after and 15 to 19 months after the trial in 37 patients. Recurrence of the vitamin D deficiency was observed after discontinuation of the supplementation.