Are you confused about how much Vitamin D you should be taking? Well you are not alone. The recommended daily allowance of Vitamin D was initially set at 400 IU per day because that was the amount necessary to prevent rickets (a brittle bone disease.) Now research is showing that supplementation could safely be between 2000 and 4000 IU per day depending on your health condition and current Vitamin D status.

It is my preference that everyone get their Vitamin D levels checked before supplementing above 1000 IU per day. Vitamin D is a fat-soluble vitamin that can be stored in the body and there is still a small risk of overdosing.

You can request a vitamin D blood test from your MD, but if they will not run it then ask us at your next appointment and we can order the test for you. The test is about $55.00 (you will still have to pay this through your MD as OHIP does not cover the cost), and it could provide invaluable information to preventing multiple chronic diseases including cancer and heart disease.

Dispelling Some Myths:

• We can get enough Vitamin D from the sun to provide us protection for the whole year

FALSE – The time of year your vitamin D levels are taken will determine your status, but, you need a constant level of vitamin D for it to be protective.  The amount of sun and the strength of the sun are equally important. It has been found that the 35th latitude (around California) is the latitude that is required to have enough strength from the sun to convert vitamin D all year round.  For everyone else, the sun is not strong enough to cause a vitamin D conversion. In fact, the journal of experimental dermalotogy in 2007 stated that the recommendations regarding sun exposure need to be reevaluated in lue of the new research on vitamin D.

• Sunscreen does not block Vitamin D conversion

FALSE – It has been found that even SPF 8 will reduce vitamin D conversion by 92.5% and SPF 15 by up to 95%.

• I drink fortified milk so I get enough Vitamin D

FALSE – Vitamin D is present in foods such as mushrooms, eggs, salmon, cod liver oil and milk. However the amount of vitamin D in a serving of milk is somewhere between 50-100IU, eggs 40IU, and salmon 500IU. You have to eat a whole lot of these to get the required amount per day.  Even mushrooms that contain a "high" amount of vitamin D,  you need to eat 5.9lbs of mushrooms per day to get enough to be protective.

• Vitamin D is very toxic

FALSE – There are very few actual studies on the toxic effects of vitamin D. One of the most common studies was done from 11 people that were fed a meal that was made from vitamin D laced peanut oil (by mistake) and ended up taking in over 5,000,000 IU of Vitamin D. Yes this wasn’t a typo…it was 5 MILLION. So, 1000IU per day is super safe for most people. In fact, studies have shown that the upper limit of vitamin D should be changed to 10,000IU (Am J Clin Nut, 1991)

• All Vitamin D supplements are equal

FALSE – First of all you need to take D3. Most pharmaceutical companies are producing D2 because it is cheaper, however it is less stable and can’t raise the vitamin D levels like the D3 version. Second, many companies will have things like lactose, gluten, magnesium stearate (coating that some people find hard to break down), and sodium benzoate in them. You want to make sure that the company that you are using uses clean raw ingredients to produce their vitamin D.  The companies that we recommend are Douglas Labs and Metagenics who have tight regulations and control on their products – both are distributed through health professionals.

So now I would love to hear from you. Which of these myths do you find most surprising? Leave your comments below and I'll have a new article for you next week on Doctor as Teacher Tuesdays!

I would also like thank my colleague, Dr. Robin Walsh, ND for initially posting this information on her blog.