Calcium and vitamin D supplements have been widely used in an attempt to prevent bone loss and prevent fractures in postmenopausal women and older men. However, evidence indicates that the absolute benefit of these treatments in terms of fracture prevention for non-institutionalised individuals is low and considerably less than that seen with licensed osteoporosis treatments. There could be benefit for those who may be deficient; particularly institutionalised individuals. The US Preventive Services Task Force has recommended against routine calcium and vitamin D supplementation in non-institutionalised elderly people.1
The target calcium intake from dietary sources and supplements should be 1000 mg per day for adults, rising to 1300 mg per day for women older than 50 years of age and men older than 70 years of age. Vitamin D from sunlight exposure (avoiding periods of high ultraviolet-radiation intensity such as in the middle of the day) and supplements should ensure 25-hydroxyvitamin D (25-OH D) levels >50 nmol/L. If vitamin D supplements are required, a dose of 800–1000 IU per day is usually sufficient, although higher doses are needed in some people to achieve target levels. Dietary calcium intake is often suboptimal in the elderly, especially institutionalised individuals.
Calcium and vitamin D supplements work by reducing secondary hyperparathyroidism and reducing bone turnover.
Bone mineral density (BMD) is also increased by calcium and vitamin D, but this effect appears to be modest. Calcium and vitamin D are not available on the Pharmaceutical Benefits Scheme (PBS) but are recommended for people likely to have insufficient intakes. This is particularly important for those taking other osteoporosis therapies.
Calcium supplements are available in two common forms: calcium carbonate and calcium citrate. Calcium tablets typically contain 250–600 mg of elemental calcium. The most commonly available type of vitamin D supplement is vitamin D3 or cholecalciferol. Vitamin D3 elevates serum 25-OH D concentrations more than vitamin D2 or ergocalciferol, and is also more reliably measured by commercially available assays. Currently available doses of vitamin D range from 400–1000 IU, available as capsules, tablets or liquid formulations.