- Prescribing Advice for GPs - https://www.prescriber.org.uk -

Calcium and Vit. D has limited effect

A paper1 published in the New England Journal of Medicine (NEJM) has concluded that Calcium and Vitamin D supplementation has limited effect in preventing hip fractures.

36,282 women aged 50 to 79 years old were recruited to this study from the Women's Health Initiative (WHI). They were randomised to Calcium and Vitamin D or placebo and followed up for 7 years. Data were collected on fracture events. A sub-group of 2,431 had bone mineral density (BMD) assessments periodically.

Despite a statistically significant rise in BMD in the group receiving Calcium and Vitamin D there was no difference in the rate of hip fractures or all fractures. A benefit was apparent in those patients who continued to take the medication and in 'higher risk' patients although women in the active arm of the study also had a greater risk of kidney stones.

There were confounders in this study; the fracture rate in the placebo arm was half the expected number, 24% stopped the study medication, only 59% were taking more than 4 in 5 doses and the dose of Vitamin D was inadequate by current standards (400IU per day rather than 800IU per day).

Action: Calcium and Vitamin D supplementation may be unsuitable for otherwise healthy postmenopausal women if fracture prevention is the aim of treatment. In women at higher risk of fractures supplementation has a positive effect and should be offered as part of a comprehensive treatment plan.


  1. Women's Health Initiative Investigators. Calcium plus Vitamin D Supplementation and the Risk of Fractures. NEJM 2006;354:669-83