Vitamin B-12 Deficiency Is Prevalent in 35- to 64-Year-Old Chinese Adults

Low vitamin B-12 status alone, or in combination with low folate status, is related to neural tube defects (NTD) and hyperhomocysteinemia, a risk factor for atherosclerotic disease, but little is known about vitamin B-12 status in Chinese adults. In a cross-sectional study, we measured plasma vitamin B-12 in 2407 apparently healthy Chinese men and women, 35-64 y old, living in the south and the north of China. Plasma vitamin B-12 concentrations were lower among the northerners than the southerners (geometric means, 209 vs. 309 pmol/L, P < 0.001). Controlling for gender, age, season (spring and fall), and area (urban and rural) had little impact on the difference. We estimated that 11% of the southerners and 39% of the northerners had plasma vitamin B-12 concentrations