Vitamin D is essential for bone health.


Vitamin D is a fat-soluble compound that must be converted to the physiologically active 1,25-dihydroxyvitamin D in the liver and kidney. Vitamin D is essential for promoting calcium absorption in the gut, as well as maintaining adequate levels of calcium in the blood. A lack of vitamin D can lead to malformation of bone.1


Where it’s found
  • Available in very few foods, such as cod liver oil and fish1
  • Also available as a dietary supplement and in fortified foods, including milk and buttery spreads1
  • Exposure to sunlight is the major source of vitamin D
    • Ultraviolet (UV) radiation converts 7-dehydrocholesterol to previtamin D3 in the skin; this is then converted to vitamin D31
    • North of the 42nd parallel (northern California to Boston), UV radiation is insufficient from November to February to meet daily requirements1
Effects on the body
  • Adequate calcium and vitamin D throughout life, as part of a well-balanced diet, will support bone health
  • Vitamin D promotes the uptake of calcium—a key component of healthy bone—from the gut. It also helps keep levels of calcium and phosphate in the blood at optimal levels to enable normal bone turnover1
    • Bone, like other tissues, is continually formed and broken down1
    • Breast-fed infants, older adults, people with limited sun exposure, people with dark skin, people with fat malabsorption, and obese people are at risk of vitamin D deficiency1
  • A number of in vitro studies have suggested that vitamin D may be beneficial in the prevention of a number of conditions due to its role as an antioxidant. Overall, more research is required to determine if this translates to true clinical benefits1
Food Nutrition Board (FNB) recommended daily intake*

Because of the importance of maintaining strong bones during aging, the recommended daily allowance for vitamin D increases with age.1

  • <50 years: 5 µg (200 IU)
  • 51–70 years: 10 µg (400 IU)
  • >70 years: 15 µg (600 IU)

*The FNB is a division of the Institute of Medicine of the National Academies.


Conclusions from the literature

Vitamin D is essential for normal bone metabolism and bone health.1


Click here to read the medical literature

Reference: 1. National Institutes of Health Office of Dietary Supplements. Dietary Supplement Fact Sheet: Vitamin D. Available at: http://ods.od.nih.gov/factsheets/VitaminD_pf.asp.