Why you need vitamin D and what it does
Vitamin D has been the hottest supplement in the past few years…and with good reason! Study after study confirms vitamin D’s role in regulating over 1000 genes in the body. With regards to preventing infections and cancer, vitamin D supplementation may turn out to be one of the biggest medical breakthroughs in decades.
The long list of conditions associated with vitamin D deficiency include: arthritis, asthma, cancer, cold/flu, depression, diabetes, eczema, fatigue, heart disease, high blood pressure, infertility, inflammatory bowel disease, insomnia, migraines, osteoporosis, psoriasis, weight gain, and the list goes on….and on!
A survey conducted by Stats Canada, found that 2/3 of the Canadian population has vitamin D levels below the amounts associated with reduced risk of chronic diseases. Translation: supplementing with vitamin D, which costs mere pennies a day, may be the key to warding off a laundry list of ailments and conditions.
Patients and students ask me this all the time. Depending on what we’re supplementing, the answer is always different. In this case, we are designed to get the majority of our vitamin D from the sun. Diet plays only a small part. When the sun hits your bare skin it reacts with cholesterol molecules to produce “pro-vitamin D” which is eventually converted into the D our body uses. The issue? Though Canadians are lucky in a number of respects (health care, beaches in PEI, The Tragically Hip….) we got the short end of the stick when it comes to geographical latitude. From October to March, even fair skinned individuals, like moi, will have trouble getting all the vitamin D they need.
I used to recommend patients expose their BARE (no sunscreen) skin to 10-15 minutes of early morning or late afternoon sun a day, for a quick 10,000 IU of “the D”. Unfortunately, new studies, that I have yet to review properly, are suggesting that in Canada we may only be able to get appropriate levels of vitamin D from the sun 2-3 months a year, regardless of exposure….and that worries me.
Okay so, how much?
Well….it really depends on your size and weight. You should consult your naturopathic doctor before starting supplementation, but here are some basic guidelines.
Infants: Health Canada recommends that “all exclusively breastfed, healthy, term infants in Canada receive 400 IU/day, and that this should continue until the infant diet includes at least 400 IU/day from other sources “. The exception: if the mother’s vitamin-D status is high enough to be providing adequate amounts of vitamin D to her baby via breast milk (see below). Babies on formula, tend to get enough vitamin D, as formula is fortified.
Children: 400 IU/day from food, supplement or both.
Adults: The typical dose is 1,000IU/day. A more aggressive, but appropriate, dose is approximately 20 IU for every pound of body weight (i.e. 3000 IU of vitamin D/day for a 150lb individual). Again, consult your naturopath before starting supps!
Pregnant/Lactating Mothers: “A dose of 4000 IU/day maintained vitamin D sufficiency in the mother and also raised vitamin D in breast milk to the point at which there was no further need of infant supplementation. Doses of this magnitude appeared safe. Even experimental doses of up to 10,000 IU/day for five months in pregnancy did not elevate levels into the toxic range”. PediatrChildHealth2007;(12)7:583-9
Note: You should be supplementing with vitamin D3 (animal source) not D2 (plant source).
“A four-year clinical trial involving 1,200 women found those taking vitamin D had about a 60-per-cent reduction in cancer incidence, compared with those who didn’t take it, a drop so large — twice the impact on cancer attributed to smoking — it almost looks like a typographical error.” (Globe and Mail, 2007, 2009)
Written By: Jillian Murphy, BSc.Kin, ND