Impact of supplementary high calcium milk with additional magnesium on parathyroid hormone and biochemical markers of bone turnover in postmenopausal women

Abstract

The aim of this study was to investigate the impact of magnesium-enriched, high-calcium milk on serum parathyroid hormone (PTH) and biochemical markers of bone turnover in postmenopausal women. We recruited 50 healthy postmenopausal women to take part in this randomised controlled study. Half of the women consumed two serves of high-calcium skim milk enriched with magnesium (milk group) and half consumed two serves apple drink per day (apple group), each for 4 weeks. The milk provided 1200 mg calcium and an additional 106 mg magnesium. We investigated the responses of serum PTH, as well as the serum and urinary calcium, magnesium and biochemical markers of bone turnover. There was no effect of time or drink on the clinical biochemistry, serum PTH or urine markers of bone resorption (free deoxypyridinoline and N-telopeptides). Serum C-telopeptides (CTX), another marker of bone resorption, did not change with time in the apple group. However, in the milk group, serum CTX deceased significantly from 0.43 +/- 0.04 ng/mL to 0.32 +/- 0.02 at 2 weeks (p < 0.0001) and 0.28 +/- 0.02 at 4 weeks (p < 0.0001). In the milk group, urinary calcium and magnesium each increased during the night but not during the day. Overall, these data suggest that milk has an antiresorptive effect on bone, but that this is not accompanied by measurable changes in serum PTH.

Nutrients in the Prevention of Osteoporosis in Patients with Inflammatory Bowel Diseases

“…The supplementation of magnesium (106 mg) and calcium (1200 mg) for 4 weeks in postmenopausal women did not change the serum parathyroid hormone level both in the study and the control group. However, the supplementation increased the serum CTX (C-terminal telopeptide) level—i.e., a bone resorption marker [ 102 ]. A conducted meta-analysis indicated that a high magnesium intake was not associated with a lower risk of hip fractures.…”

Essential Nutrient Interactions: Does Low or Suboptimal Magnesium Status Interact with Vitamin D and/or Calcium Status?

“…In a study in teenaged girls, magnesium balance was negative with calcium intakes of 1800 mg/d; however, compared with positive magnesium balance results with 800 mg calcium/d, the differences in magnesium absorption, excretion, and balance were not significant in this small crossover trial ( n = 5) ( 102 ). In a randomized clinical trial conducted in New Zealand menopausal women, researchers observed that the consumption of milk high in calcium or supplementation (1200 mg calcium) with or without magnesium significantly increased magnesium urinary excretion during the 8 h of consumption ( 103 ). Another trial in Thai menopausal women found that supplementation with 750 mg calcium for 3 mo led to a 15% increase in urinary excretion of magnesium, but the increase was not significant ( 104 ).…”

Calcium revisited, part III: effect of dietary calcium on BMD and fracture risk

“… 44 Milk not only acts on bone in children. It has been recognized already in 1985, 45 and reconfirmed later, that it inhibits bone turnover and resorption markers in postmenopausal women 46 47 48 and elderly men, and increases IGF-1. 49 …”