Many postmenopausal women take daily Vitamin D and calcium supplements with the goal of reducing the risk of fracture; however, a new government study found no benefit from the supplements for healthy postmenopausal women. In addition, they noted that taking the supplements slightly increased the risk of kidney stones. Researchers affiliated with the United States Preventive Services Task Force (USPSTF) published their findings online on February 26 in the journal Annals of Internal Medicine
The USPSTF noted that approximately 50% of postmenopausal women will suffer a fracture related to osteoporosis during their lifetime, and fractures in older adults increase the risk of death. Because calcium helps build bone, and Vitamin D helps bones absorb calcium, physicians frequently recommend taking Vitamin D and calcium supplements to prevent fractures. Surveys estimate that almost 60% of women aged 60 and over take Vitamin D supplements or calcium supplements. However, whether these supplements actually prevent fractures was not clear. For the study, the USPSTF commissioned two systematic evidence reviews and a meta-analysis on Vitamin D supplementation with or without calcium to assess the effects of supplementation on bone health outcomes in community-dwelling adults, the association of Vitamin D and calcium levels with bone health outcomes, and the adverse effects of supplementation.
The study group comprised 36,282 postmenopausal women ages 50 to 79 who took either 400 IUs of Vitamin D plus 1,000 mg of calcium daily or a placebo. The task force concluded that the current evidence is insufficient to assess the balance of the benefits and harms of combined vitamin D and calcium supplementation for the primary prevention of fractures in premenopausal women or in men. It also concluded that the current evidence is insufficient to assess the balance of the benefits and harms of daily supplementation with greater than 400 IU of vitamin D3 and greater than 1000 mg of calcium for the primary prevention of fractures in non-institutionalized postmenopausal women. Thus, the USPSTF recommends against daily supplementation with 400 IU or less of vitamin D3 and 1000 mg or less of calcium for the primary prevention of fractures in non-institutionalized postmenopausal women.
The researchers cautioned that their recommendations apply to non-institutionalized or community-dwelling asymptomatic adults without a history of fractures. Furthermore, the recommendation does not apply to the treatment of persons with osteoporosis or vitamin D deficiency. The USPSTF recommends taking a vitamin D supplement containing approximately 800 IUs for the prevention of falls in older adults ages 65 and over who are at risk for falls because they are Vitamin D deficient or because they have a history of a recent fall.
The task force also recommends screening women ages 65 and older for osteoporosis as well as younger women who are at an increased risk for fractures.
Take home message:
Despite the USPSTF recommendations, the decision regarding whether or not take vitamin D or calcium supplements should ultimately be made between a patient and his or her physician. According to the Institute of Medicine individuals require between 600 and 800 IUs of Vitamin D a day, and between 700 and 1,300 mg of calcium a day, depending on their age. Most Americans get enough Vitamin D and calcium via food intake or sun exposure (for Vitamin D); however, older adults sometimes fail to have adequate intake of these supplements and need to augment their intake with supplements.
Reference: Annals of Internal Medicine