March 15, 2016
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Q: What’s the latest research on Vitamin D?
A: Vitamin D has probably received more press clippings in the last decade than the rest of the other vitamins combined. The vast majority of its coverage has been positive as it has been linked to numerous health benefits and its potential for harm is low when it is consumed in rational amounts.
The current recommendations from Health Canada, which were updated in 2011, are for infants to receive 400 IU daily (note that Vitamin D is measured in International Units or IU as opposed to more commonly-known terms such as milligrams), for children aged one to adults aged 70 or less to receive 600 IU daily, and for those over the age of 70 to strive to achieve 800 IU daily.
Osteoporosis Canada is a little more aggressive with its targets, suggesting those aged 19-50 should consume 400-1,000 IU daily; and those over the age of 50, or younger but at high risk of deficiency, should be aiming for 800-2,000 IU per day. These recommendations are significantly higher than they were prior to 2011 but are not nearly high enough according to some researchers.
This came to a head last year when a group of researchers at the University of Alberta suggested that Health Canada had made a math error in calculating its recommendations. According to their findings, the average healthy adult should be aiming for at least 5,000 IU daily and those who are overweight should consume 15,000 IU per day. These findings were subsequently supported by other researchers at a couple of American universities and, given their controversial nature, wound up generating widespread media coverage.
All of this was enough for Health Canada to review its own calculations and recommendations to see if in fact it had erred. Health Canada's conclusion was that it had not and that the new recommendations from the University of Alberta were not supported by the data and could, in actuality, cause harm from adverse effects related to Vitamin D over-consumption.
With so many smart, well-intentioned experts lining up on opposite sides of the argument, it’s hard to know just how much you should take. Given the number of studies in the past that have shown that when it comes to vitamins and minerals, the old adage “too much of a good thing” has proven to be true (see studies on Calcium, Vitamin E, Selenium, etc.).
We prefer the middle ground that Osteoporosis Canada currently occupies (unless you are one of the few who have had blood work that gives us an idea as to just how deficient your Vitamin D levels truly are).
On other fronts, experts do agree on using supplements year-round as foods that provide Vitamin D are few and far between, and receiving it from sun exposure carries risks (i.e. skin cancer) that far outweigh the benefits.
To achieve 1,000 IU, light-skinned Canadians (those with darker skin tones would need to spend considerably longer periods of time to achieve the same levels) would need to spend 15 minutes getting sun exposure to their arms, hands and face at around noon during the spring, summer and early fall.
Keep in mind that this 15 minutes is without the use of a sunscreen, which reduces the ability of our bodies to make Vitamin D by over 90 per cent. Also keep in mind that 15 minutes of unprotected exposure to the sun at noon will likely damage your skin possibly contributing to premature signs of aging and far worse complications.
As far as food goes, decent sources of Vitamin D include tuna (154 IU per three ounces), salmon (447 IU per three ounces), eggs (41 IU per yolk) as well as Vitamin D-fortified beverages such as milk and some juices which average 100 IU per cup.
Those at risk of being low in Vitamin D include people with darker skin tones, the elderly, those with medical conditions which impair their absorption of food-based Vitamin D (such as Crohn’s disease, ulcerative colitis or celiac disease), those who stay indoors or cover themselves up when outside, and those who are overweight. This last risk group is due to the fact that fat cells hold on to the Vitamin D, thereby limiting its ability to reach the rest of the body where it can be of benefit.
The best way to know if you are deficient is to get a blood test called 25-hydroxy Vitamin D, but most experts consider this to be a waste of time and precious health care dollars for many of us.
According to a 2013 Statistics Canada report, one-third of Canadians aged three to 79 have insufficient Vitamin D levels, and 10 per cent are low enough to be deemed deficient. Given that some studies (although not all) have shown that higher Vitamin D levels have been linked to a lower risk of colorectal cancer, multiple sclerosis, lupus, high blood pressure, mental health issues, cardiovascular disease and Type 2 diabetes, it seems to be a worthwhile suggestion that most of us should at least consider taking a token amount of Vitamin D from a pill.
This suggestion comes despite the fact that as of yet, we do not know if taking a supplement will actually reduce our risk of any of these life-altering diseases. That question will hopefully be answered sometime in 2017 when the first reports from the VITAL study are expected. In this study, 25,875 men and women across the United States are being monitored to see if taking 2 000 IU of Vitamin D supplements will cut their incidence of developing cancer, heart disease and stroke. The results, needless to say, are eagerly anticipated although preliminary rumours are that the answers may be discouraging.
For more information about this or any other health-related questions, contact the pharmacists at Gordon Pharmasave, Your Health and Wellness Destination.
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