08 August 2009

Calcium with or without vitamin D

Criteria for recommending calcium to a patient should not go without considering a patient’s vitamin D status. Vitamin D status is critical for improving intestinal absorption, for maintaining calcium homeostasis, for promoting reabsorption of calcium in the kidney and is involved in bone mineralization (1;2).

Calcium supplementation along with vitamin D has been subject of at least two randomized controlled trials in Australia. The first performed on 300 elderly women (77+/- 4.6 years) found no short-term benefit as to improving absorption or promoting bone health (3). But another, longer randomized controlled trial evaluated the effects of calcium with or without vitamin D over five years (4). The researchers studied hip bone mineral density and bone turnover in elderly women (ages 70-80) in a sunny climate (4).

Thus, while short-term benefits weren’t found, long-term benefits were, which where likely produced by reduced bone turnover rate over time (3;4). In response to the studies and other research, the Australian and New Zealand Bone and Mineral Society and Osteporosis Australia issued a joint statement explaining that while calcium intake above previously established recommended levels wasn’t likely to help prevent fractures in elderly men and women, the addition of vitamin D in supplements was supported by the evidence (5).

Reference List

1. Gropper SS, Smith JL, Groff JL. Advanced Nutrition and Human Metabolism. Belmont, CA: Thomson Wadsworth, 2009.
2. Cashman KD. Calcium and vitamin D. Novartis Found Symp 2007;282:123-38.
3. Zhu K, Bruce D, Austin N, Devine A, Ebeling PR, Prince RL. Randomized controlled trial of the effects of calcium with or without vitamin D on bone structure and bone-related chemistry in elderly women with vitamin D insufficiency. J Bone Miner Res 2008;23:1343-8.
4. Zhu K, Devine A, Dick IM, Wilson SG, Prince RL. Effects of calcium and vitamin D supplementation on hip bone mineral density and calcium-related analytes in elderly ambulatory Australian women: a five-year randomized controlled trial. J Clin Endocrinol Metab 2008;93:743-9.
5. Sanders KM, Nowson CA, Kotowicz MA, Briffa K, Devine A, Reid IR. Calcium and bone health: position statement for the Australian and New Zealand Bone and Mineral Society, Osteoporosis Australia and the Endocrine Society of Australia. Med J Aust 2009;190:316-20.

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