Research Confirms Vitamin D, Calcium Essential for Bone Health
Weak bones were once considered an unavoidable part of the aging process -- but not today. We now know that people at any age can do much to keep their bones strong.
Vitamin D added to FDA Osteoporosis Risk Reduction Health Claim
In September 2008, the US Food and Drug Administration (FDA) amended its osteoporosis risk reduction health claim to reflect the importance of vitamin D, in combination with calcium, in promoting long-term bone health. The amended rule also included a broader definition of the populations that could benefit from consuming calcium and vitamin D to include both men and women of all ages and races.
The amended labeling regulation also explains that vitamin D is required for the normal absorption of calcium, and authorizes the health claim: “Adequate calcium and vitamin D throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis,” or “Adequate calcium and vitamin D as part of a healthful diet, along with physical activity, may reduce the risk of osteoporosis in later life.”
The FDA amended the osteoporosis health claim following a review of the relevant research and in response to a petition initiated by The Coca-Coca Company Beverage Institute for Health & Wellness (the Institute) in 2004. The FDA developed the osteoporosis health claim for manufacturers to include on labels of appropriate foods or dietary supplements to help consumers identify products with adequate calcium and Vitamin D that can help to support bone health.
"Osteoporosis is a growing public health crisis, and all Americans, men and women alike, will benefit from knowing that vitamin D along with calcium can help delay or prevent the onset of this disease," said Robert P. Heaney MD, FACP, John A. Creighton University Professor and Professor of Medicine at Creighton University in Omaha, Nebraska. "Along with weight-bearing exercise, the most valuable intervention for maintaining bone health is an overall healthful diet that supplies adequate amounts of all nutrients such as vitamin D."
Research Confirms Vitamin D Readily Absorbed from Skim Milk, Orange Juice
Research conducted by Dr. Michael Holick of the Vitamin D and Bone Health Research Laboratory at Boston University Medical School, demonstrated that vitamin D is readily absorbed by the body when added to skim milk and orange juice. As a result of these findings, the U.S. Food and Drug Administration (FDA) approved the addition of vitamin D to calcium-fortified juices and juice drinks in 2003.
The Importance of Vitamin D for Strong Bones
According to the U.S. Institute of Medicine (IOM), vitamin D requirements of all age groups can be met under conditions of adequate exposure to sunlight. However, several factors can reduce the production of vitamin D from the skin including the use of sunscreens, increased skin pigmentation, normal aging, and insufficient exposure to sunlight.
The main function of vitamin D is to maintain serum calcium and phosphate levels. Vitamin D aids in the body's absorption and retention of calcium, helping to form and maintain strong bones.
Updated Recommended Intakes
In November 2010, the U.S. Institute of Medicine (IOM) released updated recommendations for dietary intakes of calcium and vitamin D for North America (U.S. and Canada) from its 1997 report, including establishing a recommended dietary allowance (RDA) for vitamin D. RDAs were increased to 600 International Units (IUs) per day for all North Americans 1 to 70 years of age, including women who are pregnant or lactating, and to 800 IU per day for people age 71 and older.
According to the IOM, determining intake levels for vitamin D is complicated by the fact that blood levels of vitamin D in the body may come not only from vitamin D in the diet but also from the synthesis of vitamin D in skin from sunlight exposure. While national surveys in both the United States and Canada show the average total intake of vitamin D is among North Americans is below the median requirement, national surveys also show that average blood levels of vitamin D are above the 20 nanograms per milliliter, which is the level the IOM experts found to be needed for good bone health for practically all individuals. Since the amount of vitamin D produced via sun exposure varies greatly from person to person, and people are advised against sun exposure to reduce the risk of skin cancer, the IOM dietary recommendation assumes minimal sun exposure.
Related References
Dietary Reference Intakes for Calcium and Vitamin D
Institute of Medicine (IOM), Food and Nutrition Board. Washington, DC: National Academy Press, 2010.
Fortification of orange juice with vitamin D: a novel approach for enhancing vitamin D nutritional health. Tangpricha V, Koutkia P, Rieke SM, Chen TC, Perez AA, Holick MF. Am J Clin Nutr. 2003 Jun;77(6):1478-83.
2004 Surgeon General's Report on Bone Health and Osteoporosis.
Final Rule - Food Labeling: Health Claims; Calcium and Osteoporosis, and Calcium, Vitamin D, and Osteoporosis. Federal Register, September 29, 2008 (Volume 73, Number 189 Page 56477-56487).