A new study shows that vitamin D3 is intimately involved in several other important roles outside of optimizing bone health, indicating that daily supplementation may help improve cardiovascular and metabolic health in overweight and obese children who are vitamin D deficient.

According to the results of a clinical trial published recently in The American Journal of Clinical Nutrition, daily supplementation of 1,000-2,000 IUs vitamin D3 for six months corrected vitamin D deficiency among obese and overweight children (ages 10 to 18 years) and significantly reduced their blood pressure, fasting blood glucose levels, and improved insulin sensitivity, compared to children who received 600 IUs per day in the study. In the 1,000 IU group, central-systolic and diastolic, and systemic diastolic blood pressure were lower at 6 months compared to the 600 IU group; in the 2,000 IU group, insulin sensitivity increased at the three and six-month follow-ups, and fasting serum glucose decreased at six months. Moreover, the higher doses (1,000-2,000 IU) of vitamin D3 supplementation was extremely well-tolerated and significantly increased the children’s serum 25-hydroxyvitamin D levels without any signs of developing hypercalcemia in vitamin D deficient, overweight/obese children.

According to the National Institutes of Health, the RDA for ages 10-18 years old is 600 IU and the tolerable upper intake level is 4,000 IUs per day for (which is well above the “high dose” used in the study). This current study shows that the current RDAs are likely insufficient for those that have low vitamin D levels. There are many factors involved in an increased risk of vitamin D deficiency, such as having dark skin, insufficient sun exposure, vegan or vegetarian diets, as well malabsorption conditions such as inflammatory bowel disease or circumstances affecting fat absorption such as that seen with gastric bypass surgery. The majority of the children in the current study were African American, with a higher melanin content in the skin contributing to their overall vitamin D deficiency. Not to mention, compared to normal-weight children, obese children may need higher amounts of vitamin D in order to achieve serum 25-hydroxyvitamin D levels; “obesity does not affect skin’s capacity to synthesize vitamin D, but greater amounts of subcutaneous fat sequester more of the vitamin and alter its release into the circulation.”

Scientific literature now spotlights the intricate interrelationship that vitamins and minerals have, whether derived from food or supplemented, and how they function more optimally when taken together, versus as individual nutrients. It is well-known that vitamin D works synergistically with the other fat-soluble vitamins A, E, and K, and how crucial it is for individuals to consume adequate levels of high-quality fats in order to absorb sufficient amounts of these vitamins. In a previous article, we discuss the critical role that the mineral magnesium plays in the proper function and utilization of vitamin D. A review published in The Journal of the American Osteopathic Association found that vitamin D cannot be metabolized without sufficient magnesium levels in the body. Unfortunately, magnesium is one of the most common nutrient deficiencies, particularly in Western diets. If patients are deficient in magnesium, vitamin D will not convert to its active form, and furthermore, a deficiency in magnesium may lead to calcification of the arteries.

A study published in the Journal of Nutrition notes that, although there were limitations to the study, vitamin D deficiency in young children is linked to aggressive behavior during adolescence. Patients (including children) who have an overt vitamin D deficiency may consider supplementing with both vitamin D3 and magnesium in efforts to achieve optimal levels of both nutrients. Obviously, the most natural, inexpensive, and effective way to get vitamin D is by exposing bare skin to sunlight, so suggesting kids spend more time outside playing is a recommendation worth mentioning to help protect their bones, cardiovascular, metabolic, and behavioral health!