Lately it seems that everyone I come into contact with is Vitamin D deficient. It is estimated that 50% of the American population, 50% of kids ages 1-5 and 70% of kids ages 6-11 are deficient in this vital nutrient. We had a lively debate about it last week in one of our nutrition sessions, as there were many opinions as to the root cause of it. Some said “kids don’t play outside enough anymore”, some said “we wear too much sunscreen” and quite honestly, I’m not even sure we fully understand what the daily recommendations should be – it’s hard to say.
What exactly is Vitamin D?
The “Sunshine” Vitamin or as it is commonly known – Vitamin D is not a vitamin at all. Instead it is a prohormone synthesized by the skin when it is exposed to ultraviolet rays from the sun.
Why do we need it? Vitamin D is essential for building bones. When most of us think of building bones we tend to focus on one single nutrient – calcium. In reality it takes several nutrients including calcium, protein, magnesium, zinc, Vitamin K and oh yes, Vitamin D to build bone. Vitamin D helps absorb calcium and phosphorus from the GI tract and moves it into our bones. Since young people are growing so rapidly, they need a lot of these nutrients every day!
D FACTS: As Vitamin D levels are decreasing in children, we are seeing a re-emergence of the bone disorder Rickets. Rickets causes softening and weakening of bones in children (may produce bow legs) and is caused by prolonged Vitamin D deficiency.
Where do we find it? Of course the number one recommendation is to soak up the sun. Vitamin D from the sun seems to stay in the body longer than getting it from diet or supplements. Kids and teens that are active outside have a better chance of maintaining healthy Vitamin D levels.
The next best thing is from your diet. Cod liver oil has the highest amount followed by maitake mushrooms and fatty fish. Since plant-powered milks (think almond milk) are all the rage, they too are fortified with Vitamin D.
Lastly is to supplement. For kids and teens, the jury is still out on this. One researcher found limited benefits from giving adolescents Vitamin D supplements.
Why are we so deficient? Definitely more time spent indoors can cause it, along with reduced sun exposure from wearing protective clothing outside and increased sunscreen use. For example, using an SPF 30 sunscreen reduces your body’s ability to manufacture and use Vitamin D by 95%. Does this mean you shouldn’t wear sunscreen? Absolutely not, the cancer risk is real. Just try to balance it out. Dark skin pigmentation, health conditions like inflammatory bowel disease, obesity, living in Northern states and lower consumption of D-rich foods (especially in teens), can also cause a deficiency.
How much do we need? It has been hypothesized that we should expose our arms and legs to between 5-30 minutes of sunlight, twice a week. However, no official recommendations can be made, because sunlight can be impacted by pollution, the angle of the sun, latitude, your age, skin pigmentation (dark skin), time of day and other factors. The daily dietary recommendations currently sit at 600 IU’s a day (ages 1-70) including teenagers. The endocrine society recommends a daily intake of 1,500 to 2,000 IU’s for those that are deficient. Megadoses are discouraged.
Promising research: Some speculate that Vitamin D recommendations should be significantly higher, because it has the potential to do so much more than help build bones. Small, mostly observational studies have suggested that Vitamin D may be beneficial for preventing cancer, heart disease, diabetes; Parkinson’s and even the common cold. Long-term mega studies are already in the works on this.
So with summer coming up, know that you are not only having “fun in the sun” but also are filling up your body with a good dose of Vitamin D!