The importance of vitamin D is a hot topic, especially now as we are getting warmer weather. Vitamin D is a crucial vitamin that helps with bone health, immune function, brain health, muscle function and even protects against diseases such as multiple sclerosis and rheumatoid arthritis.
How We Get Vitamin D:
There are three ways to obtain vitamin D. The best and most natural source is from skin exposure to sunlight, secondly from vitamin D supplements and lastly from food. However, it is quite difficult to get the appropriate amounts from food.
Let’s Talk Sun Exposure:
Exposing bare skin to sunlight, specifically the ultraviolet B rays (UVB) allows the body to naturally produce vitamin D for the body. It is important to know that you don’t need to tan or burn to get the appropriate amounts of Vitamin D. Receiving vitamin D from UVB rays depends on the time of day, where you are in the world, the colour of your skin and the amount of skin exposed.
The best time of day to get vitamin D is in the mid-day, between 12-2pm, when the sun rays are at the best angle to pass through the earth’s atmosphere (for those science geeks who want to learn more about the sun check this book out). The further away you live from the equator, the less UVB rays available. Living here in Calgary means that we don’t get much for UVB rays from approximately October to April. This timeframe is when it is most important to supplement with vitamin D.
The colour of our skin and amount of skin exposed plays a large role in vitamin production as well. The darker your skin, the harder it is for your body to absorb the UVB rays. This is due to higher melanin content in darker skin, which protects against the harmful effects of sun exposure. Remember, I am not saying that those with darker skin need to tan or burn, but may need a little more time in the sun than someone with fair skin in order to receive an adequate amount of UVB rays for vitamin D production. Also, the larger the amount of skin exposed to the sun, the faster the vitamin D production. I know it can get complicated with all these factors. According to the Vitamin D Council, they suggest to “get half the sun exposure it takes for your skin to turn pink, and expose as much skin as possible”. The time taken to achieve this amount of exposure generally ranges between 10-30 minutes during peak hours of sunshine. After this amount of time it is suggested to stay in the shade, wear sun-protective clothing and use UVA and UVB protectant sunscreens to reduce the risk of burning and skin damage.
Supplementing with Vitamin D:
We are very fortunate to live in Calgary, one of the sunniest cities in Canada, however many of us aren’t ready to expose large areas of skin in the winter. This is where supplementing becomes important. Supplements are found in the forms of vitamin D2 and D3. Vitamin D3 is the vitamin D that is produced in our bodies so is the best option when buying a supplement. The supplements can be found in capsule, tablet or even liquid drops. It doesn’t really matter what form you take as vitamin D is usually easily absorbed, especially when eaten with a healthy fat (as vitamin D is a fat soluble vitamin).
The recommended dosage ranges between 600-10000 IU a day for an adult. What I recommend to make it simple, is between 2000-6000 IU/day. You may think this is high, but considering someone with fair skin produces 1000 IU’s of vitamin D in perfect conditions in just 5 minutes (according to the Norwegian Institute for Air Research and their Vitamin D/UVB Calculator) this isn’t too much. Personally, I use vitamin D drops with each drop being 1000IU, and I get between 2-6 drops a day based on how many drops fall on the spoon. You can also get your vitamin D levels checked from your medical doctor and they can evaluate whether you are low or need to adjust your levels. Vitamin D supplements are usually very safe, but if you are on certain medications, or have certain medical conditions I recommend asking your family doctor whether there may be any interactions or contraindications to supplementing.
Food Sources of Vitamin D:
As mentioned before, food isn’t the best source for us to get the right amounts of vitamin D so I am keeping this section short. You can find vitamin D in fatty fish (like wild salmon, mackerel and tuna fish), fish oil supplements, fortified milk and milk alternatives. Recent studies have shown that a palm size serving of wild salmon will give you a little under 1000 IU of vitamin D, compared to farmed salmon supplying ~250 IU. Unless you plan on eating 2-6 pieces of wild salmon a day during the winter, I definitely recommend taking a supplement and going outside in the summer.
Now let’s go outside and get some sunshine!
Written by, Dr. Shereen Kangarloo BSc. DC