Researchers at the University of Missouri (MU) recently found that obese adolescents given 4,000 IU/day of vitamin D3 for six months had significantly greater increases in their vitamin D levels than those who took a placebo. The study comes one year after the Institute of Medicine (IOM) increased the recommended daily intake levels for vitamin D.
The IOM now recommends 600 IU/day for those younger than 70. The upper safety level of vitamin D is now 4,000 IU/day and is the dose given to participants in the study titled "Safety and efficacy of using high dose (4,000 IU daily) vitamin D supplementation to improve the vitamin D status of obese adolescents."
"Obese adolescents face an increased risk for deficiency because they tend to absorb vitamin D in their fat stores, which prevents it from being utilized in their blood," said Catherine Peterson, MU associate professor of nutrition & exercise physiology.
The study found that lean adolescents require only about 100 IUs to increase their serum 25OHD levels (the main indicator of vitamin D status) by 1 ng/ml. Obese adolescents require about 200 IUs to achieve the same increase.
Vitamin D a hot topic at year's end
The end of Daylight Savings Time heralds less opportunity for sunlight, making studies touting vitamin D's benefits all the more timely. Interestingly, the volume of searches for vitamin D on Google has increased steadily since 2005, appearing to ramp up at the end of each year.
This search volume is punctuated by several top news stories over the years, including one controversial study last November that claimed North Americans get enough vitamin D and may damage their health by taking the supplement. This study gathered the greatest spike of traffic on Google's Trend graph, ahead of all the other stories touting vitamin D's benefits. More evidence, perhaps, for the doomsday nature that pervades mainstream media regarding supplements.
Functional Ingredients magazine has reported over and over, however, that vitamin D is highly beneficial for health and that many people are deficient. With one-third of American children and adolescents overweight or obese, this latest vitamin D study offers hope to help get their health back on track.