Using gas chromatography and mass spectrometry to determine 25-hydroxyvitamin D levels for clinical assessment of vitamin D deficiency

Ming-Yeh Yang ^a,1, Ching-Yuan Huang ^b,1, Tina H.T. Chiu ^c,d,

Kai-Chih Chang ^b,e, Ming-Nan Lin ^f,g, Liang-Yu Chen ^h,**, Anren Hu ^b,*

^a Institute of Medical Sciences, Tzu-Chi University, Hualien, Taiwan

^b Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu-Chi University, Hualien, Taiwan

^c Department of Nutrition Therapy, Buddhist Tzu-Chi Medical Foundation, Hualien, Taiwan

^d Department of Medicine, College of Medicine, Tzu-Chi University, Hualien, Taiwan

^e Department of Laboratory Medicine, Buddhist Tzu-Chi General Hospital, Hualien, Taiwan

^f Department of Family Medicine, Dalin Tzu-Chi Hospital, Buddhist Tzu-Chi Medical Foundation, Chiayi County,

Taiwan

^g Department of Family Medicine, College of Medicine, Tzu-Chi University, Hualien, Taiwan

^h Department of Biotechnology, Ming-Chuan University, Taoyuan City, Taiwan

Vitamin D is responsible for multiple metabolic functions in humans. Rickets are the most common disease caused by vitamin D deficiency. It is caused by poor calcium intake resulting in poor serum-ionized calcium. The purpose of this study is to develop a rapid, sensitive, and feasible method to determine the 25-hydroxy-vitamin D3 (25(OH)D3) levels in blood samples for clinical assessment. In this study, gas chromatography coupled mass spectrometry with trimethylsilyl derivatization (TMS-GC-MS) is the most suitable protocol for quantitative analyses of 25(OH)D3. Performance of method was evaluated and compared with liquid chromatography and immunoassay. Method validation has been carried out with plasma specimens. The limit of quantitation of TMS-GC-MS method is 1.5 ppb with good linear correlation. Furthermore, the dietary intake and nutritional status of vegetarian and non-vegetarians in Taiwan were assessed by our validated method. As a result, this vitamin D nutrition survey demonstrates that most Taiwanese people have insufficient vitamin D. Due to dietary habits; the male vegans may have the highest risk of vitamin D deficiency.