Calcium, vitamin D, and bone health: how much do adults need?

Purpose - The intent of this review is to provide a nutritional background for the hypothesis that excessive intakes of calcium and, possibly, vitamin D in adults and the elderly may contribute to an increased risk of cardiovascular diseases. Design/methodology/approach - Recent scientific reports and literature reviews on the linkage between excessive dietary calcium consumption and cardiovascular calcification have been assessed. Prospective human data on this health concern is limited to one recent report from New Zealand of elderly women on calcium supplements for five years. Other supporting evidence is derived from experimental studies over the years and from observations of subjects with gastric ulcers who consumed excessive amounts of milk along with antacids and of "worried well" subjects who took excessive calcium supplements or yogurt. Findings - Calcium loading in arterial walls occurs under these conditions, even among those with healthy renal function, because atherosclerotic plaques in arterial intimal layers readily permit calcium uptake from blood and the formation of bone in inappropriate locations throughout the body, especially in coronary arteries, heart valves, and arteries of other major organs. Arteriosclerotic damage in affluent populations, such as the USA, is common. Bone health seems to benefit little from excessive calcium in late life compared to the damage to arterial function. Research limitations/implications - Future studies are needed to advance understanding of this diet-disease linkage. Originality/value - This review supports recent data that indicates an important relationship between excessive calcium intakes and arterial calcification in adults and the elderly.