The impact of dietary calcium intake and vitamin D status on the effects of zoledronate
Osteoporosis International, 08/20/2012
Bourke S et al. – Baseline dietary calcium intake and vitamin D status did not alter the effects of zoledronate, suggesting that co–administration of calcium and vitamin D with zoledronate may not be necessary for individuals not at risk of marked vitamin D deficiency.Methods
- Data were pooled from two trials of zoledronate in postmenopausal women without vitamin D deficiency in which calcium and vitamin D were not routinely administered.
- The cohort (zoledronate n = 154, placebo n = 68) was divided into subgroups by baseline dietary calcium intake (<800 vs. ≥800 mg/day) and vitamin D status [25–hydroxyvitamin D (25OHD) <50 vs. ≥50 nmol/L, and <75 nmol/L vs. ≥75 nmol/L] and treatment × subgroup interactions tested.
- There were 52, 86, and 36 % of the zoledronate group and 64, 94, and 46 % of the placebo group that had dietary calcium intake ≥800 mg/day, 25OHD ≥50 nmol/L, and 25OHD ≥75 nmol/L, respectively.
- There were no significant interactions between treatment and either baseline dietary calcium or baseline vitamin D status for lumbar spine BMD, total hip BMD, the bone turnover markers P1NP and β–CTx, or the risk of an APR.
- There was also no three–way interaction between baseline dietary calcium intake, baseline vitamin D status, and treatment for any of these variables.