Vitamin D: Believe the Hype
By Megan Tempest in Food on Dec 8, 2009 5:40PM
Seriously, the recent hype surrounding vitamin D is no joke. Why? Vitamin D has a profound impact on our health. Research suggests many of us are vitamin D deficient, which may leave us vulnerable to serious health conditions, including rheumatoid arthritis, multiple sclerosis, psoriasis, and nearly 20 different forms of cancer. Many none-too-shocking factors contribute to what scientists perceive as an “epidemic” of vitamin D deficiency; our indoor-oriented lifestyles, limited sun exposure during cold-weather months, and frequent sunscreen use. Unfortunately for Chicagoans, due to the inability of UV rays to penetrate glass, we can’t make enough vitamin D by sitting next to a window or by riding in our cars to get us through the winter months.
Why do we need Vitamin D? Vitamin D is well known for its role in bone and muscle strength. Vitamin D helps us absorb calcium, which is why it is usually added to milk. Lesser known to the public is the role of vitamin D in disease prevention. Research indicates vitamin D has significant anti-inflammatory effects and is critical to optimal immune function. In August of 2009, researchers at the University of Oregon published a press release stating, “the fact that this vitamin-D mediated immune response has been retained through millions of years of evolutionary selection, and is still found in species ranging from squirrel monkeys to baboons and humans, suggests that it must be critical to their survival”.
Can we get vitamin D from food? While obtaining nutrients from food is generally the best route, dietary sources of substantial vitamin D are few and far between. Limited amounts of vitamin D can be found in fortified dairy products and cereals, as well as sardines, cod liver oil, salmon, and eggs yolks.
How much vitamin D do we need from supplements? Factors such as age, obesity, and skin color all influence our vitamin D requirements. Supplementing 1,000 IU of calcium D3 (cholecalciferol) is generally considered safe. The recommended upper limit for vitamin D is 2,000 IU per day. Although toxicity is rare, vitamin D is fat-soluble, therefore can be stored in the body for long periods. So before you start supplementing, consult your doctor. While you’re at it, considering asking for a blood test (15-hydroxy-vitamin D) that can diagnose vitamin D deficiency.