Skip to main content
. Author manuscript; available in PMC: 2017 Feb 3.
Published in final edited form as: J Nutr. 2013 Dec 4;144(2):170–176. doi: 10.3945/jn.113.183095

FIGURE 1.

FIGURE 1

Prevalence of low serum vitamin B-12 status in the absence of anemia or macrocytosis among U.S. adults aged >50 y in NHANES before and after mandatory folic acid fortification. Bars denote 95% CIs. *P < 0.001 based on prevalence estimate differences in serum vitamin B-12 deficiency (<148 pmol/L) and marginal deficiency (148–258 pmol/L) without anemia (hemoglobin ≥ 130 g/L for men, ≥120 g/L for women) or without macrocytosis (MCV ≤ 100 fL) using multinomial logistic regression adjusted for age, sex, race/ethnicity, BMI, C-reactive protein, smoking, and oral vitamin B-12 supplement use. Participants with liver disease, renal dysfunction, heavy alcohol use, and treatment of anemia <3 mo before survey participation were excluded from the analyses. Analyses were weighted to account for the complex sampling design of NHANES. MCV, mean cell volume; Serum B-12 def + no anemia, serum vitamin B-12 <148 pmol/L without anemia; serum B-12 def + no macrocytosis, serum vitamin B-12 <148 pmol/L without macrocytosis; serum B-12 marg def + no anemia, serum vitamin B-12 of 148–258 pmol/L without anemia; serum B-12 def + no macrocytosis, serum vitamin B-12 of 148–258 pmol/L without macrocytosis.