Those of you who have seen me over the years in clinic have heard me say that my advice on the need for vitamins has changed over time. This is especially true when it comes to vitamin D, which I’ve learned can make a significant difference in building bone strength for both kids and adults.
Those of us living in the Northwest do not see the sun often enough to make enough vitamin D, and thus need to supplement. The problem here is that although the sun helps our bodies make vitamin D, we just don’t see that yellow ball in the sky for nine months of the year. When it is out in the summer, you should be applying sunscreen, which protects you from the sun but unfortunately decreases your natural vitamin D production at the same time.
Most children and adults with a typical healthy diet will take in adequate amounts of the other nutrients, but with vitamin D, it’s challenging. In 2010, the Institute of Medicine increased the recommended dose of vitamin D to 600 IU for all people who are more than 12 months in age. This is up from the prior recommended dose of 200 IU. A glass of milk or fortified orange juice has about 100 IU per serving. We typically do not recommend children drink more than 2 glasses of milk a day. Cheese does not have vitamin D. Things like yogurt contain only about 40 IU per serving. Herring has about 1300 units for a small serving, but I doubt you will get your child to eat it on a regular basis. Salmon and Halibut are fantastic sources with a small serving getting us very close to our daily need but it is too costly for most households to eat on a regular basis. That leaves us with the need to supplement.
Vitamin D is important for healthy bone strength as it plays a role in calcium and phosphate regulation. This is where there is the best evidence for its benefits. It’s a fat-soluble vitamin, which means that your body stores it and thus it’s possible to get too much if excess doses are taken for a prolonged period of time, causing symptoms such as irritability, muscle weakness, elevated blood pressure or kidney stones. It’s the in-vogue vitamin these days and gets mentioned for other indications such as prevention of multiple sclerosis, cancer, and heart disease, but the evidence thus far is not as strong. More studies are necessary to really tease this out. Time will tell if it lives up to the hype, but at least we can encourage strong bones in future by getting an adequate amount now.