Scientific Task Force Issues Another Controversial Report, This Time on Vitamin D & Calcium
The recommendations on vitamin D and calcium from the U.S. Preventive Services Task Force (USPSTF) represent a limited review of the literature leading to controversial conclusions on preventing fractures in adults—which could result in widespread confusion for consumers who already are not getting enough calcium, and who further could benefit from the growing body of research that demonstrates multiple reasons to take vitamin D, said the Council for Responsible Nutrition (CRN), the dietary supplement industry’s leading trade association, in response to the report.
26 Feb 2013 --- According to CRN’s Taylor C. Wallace, Ph.D., senior director, scientific and regulatory affairs, “These recommendations fail to recognize the well-established role of calcium and vitamin D in maintaining bone health. If these recommendations are taken to heart, or misconstrued as general recommendations against calcium and vitamin D, consumers could be compromising their bone health and missing out on important other benefits from these nutrients. The bottom line: calcium and vitamin D are vital to staying healthy.”
These recommendations are not the first controversial conclusions to come out of USPSTF. Previously, the same organization recommended against both routine mammography screenings in women under 50 and breast self-examinations, as well as prostate cancer screenings for men, putting them at odds with many in the medical community. Says Dr. Wallace, “These kinds of preventative measures help save lives, and similarly, taking calcium and vitamin D are valuable preventative measures that provide a variety of health benefits, despite the outcome of one meta-analysis.”
The USPSTF’s meta-analysis was heavily reliant on the Women’s Health Initiative (WHI), the largest randomized controlled trial of calcium and vitamin D supplementation, which showed little to no effect on fracture rates in the more than 35,000 postmenopausal women in the trial. However, it turns out that many of the women in the treatment group were not adhering to their calcium regimen. And, investigators discovered that women in the placebo group were actually getting close to the IOM’s recommended levels for calcium on their own, making it difficult for the treatment group to demonstrate benefit. These limitations of the WHI are now widely acknowledged, but were ignored by the USPSTF.
Despite the limitations in the original study, a recent 2013 study by the WHI investigators reanalyzed the data, looking specifically at those women who strictly adhered to the calcium/vitamin D protocol. These results showed a significant 38 percent reduction in hip fracture and no increased incidence of kidney stone development1. The results of this latest study were not included in the USPSTF meta-analysis. Dr. Wallace comments, “The results of this latest re-analysis of the WHI data are extremely compelling.”
The USPSTF recommendations should be further reviewed and discussed within the scientific and medical communities before consumers jump to change their supplementation habits. When considering dietary supplements, consumers also need to take their individual needs and food intakes into account. CRN’s Duffy MacKay, N.D., vice president, scientific and regulatory affairs, advises, “Keep a food diary, so you know what nutrients you’re getting from your food, then consider adding calcium supplements to get what you need, based on your life stage and lifestyle. Vitamin D is harder to get from food, but it’s still important to know what your intake is; have your vitamin D levels tested by your doctor through a simple blood test. Make sure you’re communicating with your doctor, nurse practitioner or registered dietitian, whichever professional you rely on for your health decisions.” Dr. MacKay continues, “But consumers also shouldn’t be looking for magic bullets to prevent bone fractures. Instead, they should practice a combination of healthy habits, which include a role for supplements along with strength conditioning and good diet.”
1 Prentice RL, Pettinger MB, Jackson RD, Wactawski-Wende J, LaCroix AZ, Andersen GL, Chlebowski RT, Manson JE, Van Horn L, Vitolins MZ, Datta M, LeBlanc ES, Cauley JA, Rossouw JE. Health risks and benefits from calcium and vitamin D supplementation: Women’s Health Initiative clinical trial and cohort study. Osteoporosis Int 2013;24(2):567-580.
