The study was conducted on a group of 340 children aged 10 to 17 years. One-third received placebo, one-third the recommended 200IU dose of vitamin D3 (weekly dose 1,400 IU), the remaining one-third 2,000 IU daily, i.e. the weekly dose of 14,000IU.
After a year of supplementation, vitamin D levels increased slightly in the placebo group, in the second increased to 16 ng / ml in girls and 20 ng / ml in boys - which proved that it was still below 30 ng / ml - i.e. below the value that is desired for improving overall health and preventing disease. The third group managed to obtain adequate vitamin D levels - with supplementation 10 times higher dose of vitamin D than recommended.
Scientists indicate that children are permanently exposed to vitamin D deficiency, especially those who do not spend enough time outdoors and are not able to enjoy the good effects of sunlight, enabling the production of vitamin D.
"The high number of people with vitamin D deficiency is a global problem affecting people of all ages. The data on the safety of vitamin D are unconvincing, they should be modified so that children do not experience severe deficiencies, "the researchers conclude.