It’s well established that vitamin D is paramount to bone development, bone fracture resistance, and mood regulation. This “sunshine” vitamin also supports our immune and cardiovascular systems, and endocrine function, so it’s vitally important that we maintain adequate blood levels. Children especially need vitamin D to develop strong, healthy bones.
In a nation struggling with obesity, it’s hard to believe that we are once again seeing borderline deficiencies. Though rickets, scurvy, and pellagra seem like stories from the days of pirates and early settlers, modern science shows that we are now seeing borderline and frank deficiencies of many vitamins and minerals in the American population. It is clear that though we are overfed, we are undernourished. Furthermore, our messages regarding low-salt and skin-cancer awareness have decreased consumption of iodine and significantly impacted vitamin D levels.
Perhaps the most concerning takeaway from modern nutritional data is that children, particularly obese, minority children, seem to be heavily impacted. The National Health and Nutrition Examination Survey (NHANES) study found that a large number of children 6-18 years of age are deficient in vitamin D. The deficiency percentage goes way up in children who are overweight, and amongst obese kids – one third of white, 50% of Latino, and 87% of African American children – were deficient in vitamin D.
Why are we lacking?
With so many fortified foods in our grocery stores and the ability of our body to make vitamin D with exposure to sunlight, why are so many kids lacking?
The most obvious answer is probably the fact that all of us, including our kids, are spending more and more of our lives indoors and engaged in sedentary pursuits, such as watching TV and working/playing on our computers and smartphones. Not only are we spending less time outdoors, we are also much more aggressive about using sunscreen to protect our skin, which dramatically decreases our ability to make vitamin D.
While vitamin D is found in some foods, it is not easy to get adequate amounts in our diet. For example, to get just 600 IU of vitamin D in your diet you would need to eat one of the following everyday:
* 3–4 ounces sockeye salmon, cooked
* 11.4 ounces water-packed tuna
* 26 oil-packed sardines
* 15 large eggs
* 5 cups fortified milk OR
* 30-45 ounces yogurt
In the case of vitamin D, the best bet to ensure adequate intake is probably through the use of supplements, which are readily available in pharmacies and natural foods stores. In general, breastfed infants should be given 400 IU per day; older children 1000 IU per day, while obese children probably need closer to 2000 IU per day. Talk to your pediatrician to know what is best for your child. When choosing a vitamin D supplement, look for those that contain D3 (cholecalciferol), the most bioactive form, and take with dinner for optimal absorption.
More is not better
While you want to make sure you and your kids are getting adequate vitamin D – more is not better. The Institute of Medicine has set the following upper limits for vitamin D, meaning you should NOT exceed these amounts unless under the supervision of your health care provider.
* 1,000 IU/day for infants to age 6 months
* 1,500 IU/day for ages 6 months to 1 year
* 2,500 IU/day ages 1 to 3 years
* 3,000 IU/day for ages 4 to 8 years
* 4,000 IU/day anyone older than 8 years
Vitamin D, like most nutrients, does best when it is taken with its partner nutrients. Vitamin D partners well with calcium and vitamin K2. Vitamin D allows calcium to be absorbed and vitamin K2 directs it to the bone. I write about this extensively in my book, Fortify Your Life, if you want to learn more.
Turer CB, et al. Prevalence of vitamin D deficiency among overweight and obese US children. Pediatrics 2013; 131(1):e152-61