Vitamin D requirements differ from person to person and is even dependant on the ethnic groups. A study published in the ‘Metabolism, Clinical and Experimental’ journal said that those with less than 20 nanograms of Vitamin D per millilitre of blood have deficiency.
Whereas, the Endocrine Society has set a higher threshold of 30 nanograms. “Recommendations based on earlier studies using a number of different tests for vitamin D levels persist and, not surprisingly, current guidelines vary,” said author Sylvia Christakos, a professor at Rutgers New Jersey Medical School.
“For example, it is not clear that the most optimal levels for vitamin D are the same for Caucasians, blacks or Asians alike. More laboratories are now implementing improved tests and efforts are being made to standardize results from different laboratories,” Christakos added.
Vitamin D’s main function is to ensure that our body absorbs calcium. A deficiency of vitamin D can cause delayed development of the skeletal system as well as rickets in children. Adults with deficiency are also at an increased risk of fractures and osteoporosis.
Calcium supplements are not enough for to prevent rickets. Vitamin D should be consumed along with them to get optimum results. Elderly people will benefit from taking these supplements. But excess of vitamin D is harmful as well. High doses increase the risk of fracture. The National Academy of Medicine recommends 400 iu/day for infants, 600 iu/day for people age 1 to 70 and 800 iu/day for people over 70.
Some studies have proven that Vitamin D supplementation has reduced mortality and others suggest that it is good for immune function, cancer and cardiovascular health. Christakos said a consistent benefit of vitamin D supplementation has yet to be shown. However, Christakos noted that most studies have not discriminated between participants who are vitamin D sufficient or deficient.