Vitamin B12 intake above current recommendations may be needed to ensure optimal vitamin B12 status in sub‐groups of healthy adults

Abstract

The study objectives were to assess vitamin B12 (B12) intake and status of non‐supplement consuming healthy young (18–49 y) adults (n=299) and to characterize dietary patterns most likely associated with normal B12 status. Vitamin B12 status was assessed by plasma B12, serum MMA, and serum holo‐TC. Dietary intake was estimated using a modified Dietary History Questionnaire and reduced rank regression was used to identify dietary patterns predicting B12 status. Vitamin B12 status was abnormal for at least one biomarker (B12 < 148 pmol/L, MMA > 270 nmol/L, holo‐TC < 35 pmol/L) in 30% of individuals (23% meat consumers and 42% non‐meat consumers). Dietary patterns predicting variance in B12 biomarkers consisted primarily of fortified foods (eg RTE breakfast cereals and vegetarian meat substitutes), and fish, which were positively associated with vitamin B12 status. The median B12 intake associated with high vs normal MMA and low vs normal holo‐TC was 2.9 vs 4.7 g/d and 3.0 vs 4.8 g/d, respectively. The median B12 intake associated with the cut‐off for normal B12 status ranged from 3.2 to 4.1 μg/d for all biomarkers. Based on regression analysis, these data suggest that vitamin B12 requirement of healthy young adults may currently be underestimated. Individuals who wish to reduce meat consumption somewhat, may enhance B12 intake by including fish and fortified foods in their diet.