Pharmacotherapeutic group: Calcium, combination with vitamin D and/or other drugs
ATC code: A12AX
Vitamin D increases the intestinal absorption of calcium.
Administration of calcium and vitamin D
3
(colecalciferol) counteracts the increase of parathyreoid hormone (PTH), which is caused by calcium deficiency and which causes increased bone resorption.
A clinical study of institutionalised patients suffering from vitamin D deficiency indicated that a daily intake of two tablets of calcium 500 mg/Vitamin D 400 IU for six months normalised the value of the 25-hydroxylated metabolite of Vitamin D
3
and reduced secondary hyperparathyroidism and alkaline phosphatases.
An 18-month double blind, placebo controlled study including 3270 institutionalised women aged 84±6 years that received supplementation of vitamin D (800 IU/day) and calcium phosphate (corresponding to 1200 mg/day of elemental calcium), showed a significant decrease of PTH secretion. After 18 month, an “intent-to treat” analysis showed 80 hip fractures in the calcium-vitamin D group and 110 hip fractures in the placebo group (p=0.004). A follow-up study after 36 months showed 137 women with at least one hip fracture in the calcium-vitamin D group (n=1176) and 178 in the placebo group (n=1127, p<0.02).
