Cardiovascular Calcification and Bone: A Comparison of The Effects of Dietary and Serum Calcium, Phosphorous, Magnesium and Vitamin D

This comparison of the effects of calcium, phosphorus, magnesium and vitamin D on cardiovascular (CV) calcification and bone has shown that in general the micronutrients that promote bone health also protect the arteries. We have shown that adequate amounts of all three minerals should be ingested, paying particular attention to supplementing calcium to bind high phosphorus and to ensure the maximum benefit from supplementing vitamin D. It appears that the optimum intake for bone is >800 mg/d calcium, with postmenopausal women possibly requiring a total intake of >1100mg/d. Both CV and bone studies suggest achieving a serum 25(OH)D level of >75nmol/l. These relationships are valid for a Caucasian population, however, and may not hold in African Americans and Asians. The recent concerns that calcium supplementation may increase CV disease risk has largely proved groundless, with higher calcium intake improving dyslipidaemia, hypertension and mortality. With respect to higher serum phosphate, there is an association with CV calcification and CVD risk even within the normal range, suggesting that the reference ranges may need to be redefined for ‘at risk’ patients. CV calcification was reduced in CKD patients with magnesium intake in the range 384 669mg/d. When considering the complex interplay of the action of the minerals together with their regulators vitamin D, PTH and FGF23, it is clear that this is a very sophisticated system which attempts to maintain calcium homeostasis to the possible detriment of bone and arteries. This reinforces the need to ensure adequate calcium intake before supplementing vitamin D.