Having an Adequate Intake of Vitamin D and Calcium is Not an Option 26 Feb 2013
Left hand, right hand. Increase taxes, reduce spending. A good diet is sufficient, taking a dietary supplement provides insurance. What should I do? Who to listen to? Well, today’s blog is about the middle majority. The majority trying to eat a balanced diet, trying to make nutrient-rich food choices, and regularly using dietary supplements as insurance.
The US Preventive Services Task Force (USPSTF) conducted two systematic reviews and a meta-analysis to weigh the pros and cons of supplementing with higher doses of calcium and vitamin D. Data from studies involving community-living (noninstitutionalized) without a history of fractures. Based on selected studies, the USPSTF concluded there was insufficient evidence to confirm that taking a 1,000 mg calcium supplement with 400 IU vitamin D daily would prevent primary fractures.
One of the challenges of meta-analysis is that the conclusion can only reflect the quality of the studies which were included in the analysis. This report primarily evaluated the effect of supplement use (yes/no). As noted in the Council for Responsible Nutrition response, this recommendation was heavily weighted by data collected from 35,000 women who participated in a randomized controlled trial, i.e. the Women’s Health Initiative, where many were not adhering to the calcium regimen. A more re-analysis of women who strictly adhered to the calcium and vitamin D supplementation found a 38% reduction in hip fracture and no increased risk of kidney stones.
Here are the facts: 1) About every other postmenopausal women will suffer a fracture related to osteoporosis. 2) Calcium and vitamin D supplementation reduces rates of bone loss in older people. 3) Vitamin D deficiency is prevalent in the US, the majority of Americans have serum 25(OH)D levels < 50 nmol/L, and 400 IU vitamin D3 daily does not meet the DRI.
The International Osteoporosis Foundation (IOF) agrees with the USPTF that daily supplementation with doses of vitamin D ≤ 400IU and calcium ≤ 1,000mg has no net benefit. That is because the “IOF finds that a higher dosage of vitamin D, specifically 800 IU/d, does reduce fractures”.
No one disputes the role of calcium and vitamin D in maintaining strong bones. The debate among health professionals, experts, and professional bodies is philosophical. Basically, should they advise people to meet their nutrient requirements exclusively from the foods they eat? But what if people don’t always make good food choices? Is there value in using a dietary supplement? Of course. But some health professionals believe that recommending supplements is an admission of dietary failure. And rightfully, over-consumption can be an issue for 1-3% of people. The decision by health professionals and professional bodies to recommend foods versus foods and dietary supplements is a value decision, it is not a statement on the essentiality of calcium and vitamin D.
There is no debate about the importance of an adequate intake of vitamin D and calcium. These nutrients are essential to maintain strong bones and muscles to reduce the risk of falls and fractures. Everyone should be consuming the recommended daily intakes for vitamin D and calcium. -mm-
Citations
Prentice RL, Pettinger MB, Jackson RD, Wactawaski-Wende J, LaCroix AZ, Anderson GL, Chlebowski RL, 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. 2013 Osteoporosis Int doi: 10.1007/s00198-012-2224-2.
