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US experts question value of low-dose calcium and vitamin D supplementation for bone health

February 27, 2013

According to an U.S. expert panel, healthy postmenopausal women are not being recommended to add low-dose supplements with calcium and vitamin D to their diet as there is not enough evidence to determine whether it helps to prevent broken bones. These recommendations do not apply to people who already have been diagnosed with osteoporosis, a history of fractures or falls or are living in an assisted-living community.

The U.S. Preventive Services Task Force reviewed data of past research which investigated whether supple-ments of vitamin D and calcium can prevent fractures in addition to dietary intake (1). Based on two reviews, the panel found there were no benefits but a small increase in the risk of developing kidney stones for post-menopausal women taking low-dose vitamin D and calcium supplements – below 400 IU and 1,000 milligrams per day, respectively. They also found that there is not enough evidence to suggest higher doses of the vitamins are effective or safer for older women, or that taking any dose of the supplements help men or younger women.

The researchers commented that for men and younger women, their recommendation is not: do not take calcium and vitamin D supplements. However, there is simply not enough known right know. They added that these recommendations do not apply to people who have already have been diagnosed with osteoporosis, have history of fractures or are living in assisted-living communities. Women aged 65 and older should be screened for the bone-weakening disease osteoporosis, and so should younger women who have a higher risk of broken bones. The panel also recommends that senior citizens with a history of falls and vitamin D deficiency take supplements to help strengthen muscles and help with balance. Experts noted that good studies on vitamin D are difficult to do and to interpret and that evidence-based scientific consensus seems impossible to achieve. However, studies continue to show beneficial effects of calcium and vitamin D supplements on bone health: a recent re-analysis of the Women’s Health Initiative (WHI) – the largest randomized, double-blind, placebo-controlled clinical trial which involved 36,282 postmenopausal women receiving a daily dose of 1,000 mg elemental calcium carbonate plus 400 IU of vitamin D3 or placebo for an average if seven years showed a 38% reduction in hip fracture and no increased incidence of kidney stone development for women who strictly adhered to the study protocol (2). The results of this latest study were not included in the panels review.

Every year approximately 1.5 million Americans suffer from breaks that are tied to brittle bones. It has been suggested that about half of all women over 50 years of age will end up with a break that is linked to the bone-weakening disease osteoporosis – a major concern because broken bones are linked to chronic pain, disability and increased risk of sickness and early death. Vitamin D has also been investigated as a preven-tive measure against dementia, heart disease and cancer, but with inconsistent results.

References

  1. Moyer V. A. et al. Vitamin D and Calcium Supplementation to Prevent Fractures in Adults: U.S. Preventive Services Task Force Recommendation Statement. Annals of Internal Medicine. Published online February 2013.
  2. Prentice R. L. et al. Health risks and benefits from calcium and vitamin D supplementation: Women's Health Initiative clinical trial and cohort study. Osteoporosis International. 2013; 24(2):567-580.