Home | Business News | Browse by Publication | N | Nutrition & Dietetics: The Journal of the Dietitians Association of Australia

Does the vitamin D status of Australians and New Zealanders need improving and how do we do it?

Article Excerpt
Vitamin D insufficiency in Australia and New Zealand was thought to be limited to certain high-risk groups such as institutionalised elderly, veiled women and their breastfed infants. The remainder of the population was assumed to receive sufficient vitamin D from sunlight exposure. Recent surveys in both countries have cast doubt on this assumption. (1-4) For example, almost 50% of New Zealand children and adults were deemed to be vitamin D-insufficient in national surveys, based on low serum 25 hydroxyvitamin D concentrations (<50 nmol/L), the best indicator of vitamin D status. (3,4) Vitamin D concentrations were much lower in the winter than summer and in Pacific People than Europeans, suggesting that skin colour and season are important determinants of vitamin D status. These findings are consistent with reports from several other countries. (5,6)

Do low circulating 25 hydroxyvitamin D concentrations pose a health risk to Australians and New Zealanders? Although reportedly on the rise the prevalence of rickets and osteomalacia is probably low outside of high-risk populations. (7) Of greater public health concern is that vitamin D insufficiency, not severe enough to cause rickets or osteomalacia, may increase the risk of osteoporotic fracture and other negative health outcomes. Vitamin D insufficiency leads to poor calcium absorption, a compensatory rise in parathyroid hormone leading to accelerated bone loss and increased risk of osteoporotic fracture. Low vitamin D status has also been associated with a number of non-skeletal outcomes such as increased falls, poor dental health and increased risk of type 1 diabetes as well as certain types of cancer. (8) Is vitamin D status causally related to these non-skeletal outcomes? Ultimate...