Studie ukazuje první krok k vývoji testu pro měření stavu vitaminu D ze vzorků vlasů
Více než 1 miliarda lidí na celém světě má nedostatek Vitamín D. This deficiency affects primarily bone health and also increases one’s risk of cardiovascular nemoc, cukrovka, rakovina etc. Due to this implication assessment of Vitamín D has gained interest. Vitamin D se měří přes a krevní test which measures the concentration of best biomarker of Vitamín D v krev called 25-hydroxyvitamin D (25(OH)D3). The krev sample needs to be collected in hygienic conditions under trained medical personnel. This test is an accurate estimate but its biggest limitation is that it reflects status of Vitamín D at a single time point and does not account for high variability of Vitamín D thus requires frequent sampling. A single value may not be an ideal representation as Vitamin D levels could differ in our body depending upon season or other factors. The test is expensive and a cost burden especially in low-and-middle-income countries. But, because high proportion of population is now deficient in Vitamín D this krev test is being increasingly requested.
Studie zveřejněná v Živiny led by Trinity College, Dublin has shown for the first time that Vitamín D can be extracted and measured from human hair1. Authors themselves provided three hair samples for the study, two harvested from crown area of the scalp and one from beard, which were cut into 1cm length, weighed, washed and dried. 25(OH)D3 was extracted from these samples using the same procedure used to extract steroid hormones from hair2 in which a mathematical formula takes measured concentrations of the biomarker using Liquid chromatography-Mass Spectrometry (LC-MS) or Mass Spectrometry (MS) and provides an approximation of concentration in the hair. At the same time, krev from all tissue samples was also analyzed using MS. Quantifiable concentrations of 25(OH)D3 present in both hair and beard samples were measured validating feasibility of such a measurement.
Human hair grows approximately 1 cm every month and Vitamín D is deposited to the hair continuously. More Vitamín D is deposited to hair when levels of Vitamín D v krev are high and less is deposited when they are low. A test which could measure vitamín levels from hair can tell us about Vitamin D status over a longer duration – several months at least taking into account seasonal differences. The longer one’s hair, more accurately status of Vitamin D can be measured, example several months to years and this could be treated as a long-term record.
This is an inexpensive, non-invasive method to capture Vitamín D status and can help medical professionals to maintain levels of Vitamin D concentrations in a person over time. The exact association between Vitamin D in krev and in hair over a period of time needs further research as factors such as hair color, hair thickness and texture could affect Vitamín D in hair.
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Zdroje)
1. Zgaga L a kol. 2019. Měření 25-Hydroxyvitaminu D v lidských vlasech: Výsledky studie Proof-of-Concept. Živiny. . 11 (2). http://dx.doi.org/10.3390/nu11020423
2. Gao W a kol. 2016. Analýza endogenních steroidních hormonů v lidských vlasech založená na LC-MS. J. Steroid Biochem. Mol. Biol. 162. https://doi.org/10.1016/j.jsbmb.2015.12.022
