A-082 Prevalence of Vitamin D2 Toxicity in American Population

Abstract Background Vitamin D supplementation by human individuals has significantly increased in the world. In US the total stored 25-OH-Vitamin D3 and 25-OH-Vitamin D2 has significantly increased for both in summers and winters. Under sunlight exposure, 7 dehydrocholesterol is converted to Vitamin D3 and is endogenous source in mammals. However, most of the exogenous source for Vitamin D used to be Vitamin D2 which used to be extracted only from mushrooms but is now manufactured by supplement industry as well. In last decade most of the supplementation has been due to chemically synthesized Vitamin D3. Food is now supplemented by both D2 and D3. It is not clear what is the prevalence of D2 supplementation/consumption in American population. Competitive immunoassays do not consistently recover 25-OH-D2 compared to 25-OH-D3 and some antibodies used have variable or no cross reactivity with 25-OH-D2. LC-MS/MS method can easily distinguish the two and can help in providing the precise and accurate results for 25-OH-D2 and 25-OH-D3. Here we present what is the prevalence of Vitamin D2 consumption and toxicity in American population based on our LC-MS/MS methods. Methods The study measured vitamin 25-OH-D levels (total, D2, and D3) in 148,654 patients from Mayo Clinic as well as from other medical centers within the U.S. Patients age ranging from new-born babies to over 100 years, and represents Male, Female and Neutral genders. Samples were analyzed for 25-OH-Vitamin D by LC-MS/MS as published earlier. Unlike immunoassays, LC-MS/MS gave us separate results for 25-OH-D3 and 25-OH-D2 with 100 percent specificity. Results 25-OH-Vitamin D2 levels of greater than 10 was present in at least 10,358 and ranged from 10 to 205 ng/mL. Of 10,358, 51 percent had 20-50 ng/mL, 10 percent had 51-80 ng/mL, and 1.3 percent had >80 ng/mL, ranging from 81-205 ng/mL with a median of 92 ng/mL. Of the patients found at Total Vitamin D >80 ng/mL, toxic levels of both D2 and D3 were found more in females than males. There was no significant gender difference for Vitamin D3 consumption but for D2 consumption, mean and median levels were different in males and females. Conclusion Clinical lab testing should accurately measure both 25-OH-D3 and 25-OH-D2, otherwise the patient total Vitamin D values in circulation will be underestimated.