A Non-Invasive Hair Test to Determine Vitamin D3 Levels

The study developed a non-invasive assay to measure Vitamin D levels using hair samples from 70 male university students, aiming to provide a quarterly average level of vitamin D status. The assay, based on liquid chromatography-mass spectrometric analysis, detected the primary form of vitamin D (25OHD3) in hair samples, with levels ranging from 17 to 1541 pg/mg. However, 21 samples had levels below the assay's lower limit of detection (10 pg/mg). The mean and standard deviation of detectable 25OHD3 levels were 276.7 ± 329.9 pg/mg. The study concludes that the hair test for vitamin D shows promise as a complementary clinical assay to blood tests, offering a longer-term view of vitamin D status, but acknowledges limitations such as a small sample size and a lack of diversity in hair types and demographics, indicating the need for further research.