Effects of Vitamin D on Human Body and the Measurement Methods: A Systematic Review

Abstract

Background:

Vitamin D is a fat-soluble metabolite, which can be mainly obtained from skin exposure to the sunlight. Foodstuffs containing vitamin D such as oily fish, eggs, and mushrooms are other sources for this vitamin. Vitamin D plays its role in the body via its intracellular receptor. The discovery of vitamin D receptors on a wide range of body tissues indicates the broad effects of this metabolite on the human body. The aim of this study was to investigate vitamin D mechanisms and measurement methods.

Materials and Methods:

In this study, out of 72 primary articles searched in PubMed and Google Scholar databases from  2012 to 2017, 16 articles with the keywords vitamin D, gold-standard methods, pharmaceutical forms, and body organs were selected and studied.

Results:

Studies have shown the effects of vitamin D on almost all body organs, including skin, bone, liver, intestine, and muscles. Some hormonal functions are also correlated with vitamin D. Since vitamin D deficiency may interfere with numerous mechanisms in the body, taking vitamin D supplements would have significant effects on preventing many diseases.

Conclusions:

 As vitamin D deficiency is quite common worldwide, it is recommended to measure vitamin D levels annually and to take vitamin D supplements under the supervision of a physician. The reference method used for vitamin D concentration assessment is liquid chromatography-tandem mass spectrometry. Other measurement techniques have also been used in order to quantify this metabolite, such as immunoassays and chemiluminescence assays.