It seems that every day we learn more about the health-promoting effects of fat-soluble vitamin D. Known as the sunshine vitamin because we manufacture it in response to skin contact with UV sun rays, it’s one of the few vitamins our bodies can synthesize. Some researchers suggest we need up to 30 minutes of sun exposure between 10 AM and 3 PM at least twice a week to the face, arms, legs, or back without sunscreen for sufficient creation of vitamin D – making it a challenge for many people and raising concerns about skin photoaging and cancer.
Likewise, UV rays from tanning beds can trigger synthesis of D, but come with an increased risk of melanoma. Factors Impeding D Formation:
• Complete cloud cover (50%)
• Shade (60%)
• Smog (60%)
• Glass/ Windows
• Sunscreen with SPF 8 + higher
• Dark skin
Naturally rich dietary sources of vitamin D are few and far between, and include different varieties of fish (tuna, mackerel, cod liver oil). Vitamin D is also available in goat’s milk, shiitake mushrooms and eggs. Fortified foods, including milk, are other food sources of this essential nutrient. (Note that vitamin D is typically not added to cheese and other dairy foods.) As a fat soluble nutrient, digestion and absorption of vitamin D can be a problem for those with challenged digestion. Use of digestive enzymes can boost absorption of vitamin D as well as other nutrients.
Why We Need it:
New research is starting to uncover exactly how D helps our bones: it promotes calcium absorption, and is necessary for bone growth and remodeling.
But its benefits don’t stop at your skeleton. Vitamin D also modulates cell growth, and supports both immune and neuromuscular function. We also know that D is a factor in cell proliferation, differentiation and apoptosis (programmed cell death.) Vitamin D is such an important nutrient that many cells have vitamin D receptors, and some convert D into its more potent (D3) form.
Vitamin D deficiency is the world’s most common deficiency. For optimal benefits to the musculoskeletal systems, cardiovascular system, immune system and robust health requires daily vitamin D intakes of at least 1,500 IU. Studies show that long-term daily intakes up to and including 10,000 IU of vitamin D safely maximize benefits. As some medications interfere with vitamin D metabolism, discuss your prescription with your health care provider to determine your requirements.