A lot of confusion exists over Vitamin D, it’s optimal levels and how best to obtain them. Various organizations are recommending that adults supplement with increased levels. The Canadian Cancer Society recommends 1,000 international units daily from October to March (when most Canadians don’t get much sun); the American Academy of Pediatrics (AAP) recently issued a report stating that children should be consuming double the usually recommended levels of vitamin D—400 International Units (IUs) of the vitamin per day, compared to the 200 IUs previously recommended by AAP; and, a group of 18 scientists from the University of California said recommended daily intakes of vitamin D should be raised to 2,000 International Units for vitamin D3. Meanwhile, others are wary of the possibility of overdose.
What Is Vitamin D?
Vitamin D refers to two biologically inactive precursors—D3, also known as cholecalciferol, and D2, also known as ergocalciferol. Not really a vitamin, vitamin D3 acts more like a hormone and it is produced in the skin upon exposure to UVB radiation (290 to 320 nanometers). While we’ve known for a long time that it is important for absorbing calcium and building bones, new research keeps coming out suggesting that vitamin D deficiency can lead not just to osteoporosis but possibly to heart disease, multiple sclerosis, diabetes, even cancer. It’s believed to impact the immune system and perhaps even brain function.
Balancing Skin Safety With Recommended Levels
With an increased awareness of skin cancer and the risks associated with unprotected UV exposure, it’s not surprising that many of us are either avoiding the sun or covering up with sunscreen. Recent estimates suggest that because of our sun safety, about one billion people are deficient in vitamin D. Even if you try to consume foods containing vitamin D, it will be difficult to obtain substantial amounts through diet alone.
If you don’t spend much time outdoors, live in a Northern climate or wear sunscreen when you go out, then you might want to consider supplementing. 1000 ius daily is considered a good dose for most adults. Until we know more, most experts recommend 2000 iu as a safe upper limit. Check with your physician for guidelines if you’re not sure what’s best for you.
