In sickness and in health: pivotal role of vitamin D

• Published in: Biochemia medica 2020-06, Vol.30 (2), p.020501-214
• Main Authors: Nikolac Gabaj, Nora, Unic, Adriana, Miler, Marijana, Pavicic, Tomislav, Culej, Jelena, Bolanca, Ivan, Herman Mahecic, Davorka, Milevoj Kopcinovic, Lara, Vrtaric, Alen
• Format: Article
• Language: English
• Subjects: Animals; Cardiovascular Diseases - blood; Chromatography, Liquid; diabetes mellitus; Diabetes Mellitus - blood; extravascular body fluids; Female; Fertility; Hemolysis; Humans; Hyperlipidemias - blood; Jaundice - blood; Lung Diseases - blood; Male; Neoplasms - blood; polymorphism; preanalytical variability; Review; Rheumatic Diseases - blood; Seasons; Tandem Mass Spectrometry; vitamin D; Vitamin D - blood; Vitamin D - physiology; Vitamin D Deficiency - blood; Vitamin D Deficiency - physiopathology
• ISSN: 1330-0962; 1846-7482
• DOI: 10.11613/BM.2020.020501

Within the last several years, frequency of vitamin D testing has multiplied substantially all over the world, since it has been shown to have an important role in many diseases and conditions. Even though liquid chromatography - tandem mass spectrometry (LC-MS/MS) has been identified as "gold standard" method for vitamin D measurement, most laboratories still use immunochemistry methods. Besides analytical problems (hydrophobicity, low circulating concentrations, ability to bind to lipids, albumins and vitamin D binding protein, presence of multiple vitamin D metabolites and variable ratios of 25(OH)D and 25(OH)D in the blood), vitamin D shows great preanalytical variability, since its concentration is drastically influenced by seasonal changes, exposure to sun, type of clothes or sun block creams. Vitamin D is mostly measured in serum or plasma, but new studies are showing importance of measuring vitamin D in pleural effusions, breast milk, urine, synovial fluid and saliva. Besides the main role in calcium homeostasis and bone metabolism, many studies linked vitamin D deficiency with cancer, cardiovascular diseases, diabetes, fertility and many other conditions. However, even though initial observational studies indicated that supplementation with vitamin D might be beneficial in disease development and progression; first results of well-designed randomized controlled prospective studies did not find differences in frequency of cardiovascular events or invasive cancer between patients taking vitamin D supplementation compared to placebo. In the light of these recent findings, validity of excessive vitamin D testing remains an open question.