Vitamin B-12 supplementation of rural Mexican women changes biochemical vitamin B-12 status indicators but does not affect hematology or a bone turnover marker.
A high prevalence of low serum vitamin B-12 concentrations has been reported in studies and surveys in Latin America including Mexico, but the functional consequences are unknown. This randomized controlled trial assessed the response to a high-dose vitamin B-12 supplementation of women in rural Querétaro, Mexico. Participants aged 20-59 y were stratified at baseline to deficient, marginal, and adequate status groups (serum vitamin B-12, 75-148, 149-220, and >220 pmol/L, respectively), and each group was randomized to vitamin B-12 treatment (single dose of 1 mg i.m. then 500 μg/d orally for 3 mo, n = 70) or placebo (n = 62). Measures at baseline and 3 mo included: complete blood count, serum vitamin B-12, holotranscobalamin (holoTC), folate, ferritin, C-reactive protein (CRP), bone alkaline phosphatase, and methylmalonic acid (MMA) and plasma total homocysteine (tHcy). At baseline, 11% of the women were vitamin B-12 deficient and 22% had marginal status. HoloTC was low (<35 pmol/L) in 23% and correlated with serum vitamin B-12 (r = 0.7; P < 0.001). Elevated MMA (>271 nmol/L) and tHcy (>12 μmol/L) occurred in 21 and 31%, respectively, and correlated with serum vitamin B-12 (r = -0.28, P < 0.0007 and r = -0.20, P < 0.01, respectively). Supplementation increased serum vitamin B-12 and holoTC and lowered MMA and tHcy, normalizing all values except for elevated tHcy in 21% of the women. Supplementation did not affect hematology or bone-specific alkaline phosphatase. Vitamin B-12 supplementation normalized biochemical indicators of vitamin B-12 status in the treatment group but did not affect the functional outcomes measured.
USDA, Agricultural Research Service Western Human Nutrition Research Center, Davis, CA, USA.
Setareh
S
Shahab-Ferdows
Miriam A
MA
Anaya-Loyola
Haydé
H
Vergara-Castañeda
Jorge L
JL
Rosado
William R
WR
Keyes
John W
JW
Newman
Joshua W
JW
Miller
Lindsay H
LH
Allen
D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood; D016723:Bone Remodeling; D002097:C-Reactive Protein / Q000378:metabolism; D019587:Dietary Supplements; D005260:Female; D005293:Ferritins / Q000097:blood; D005492:Folic Acid / Q000008:administration & dosage / Q000097:blood; D006710:Homocysteine / Q000097:blood; D006801:Humans; D016015:Logistic Models; D008764:Methylmalonic Acid / Q000097:blood; D008800:Mexico; D008875:Middle Aged; D009752:Nutritional Status; D012424:Rural Population; D014805:Vitamin B 12 / Q000008:administration & dosage* / Q000097:blood; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000503:physiopathology; D014803:Vitamin B Complex / Q000008:administration & dosage* / Q000097:blood; D055815:Young Adult
D006710:Homocysteine; D014803:Vitamin B Complex; D008764:Methylmalonic Acid; D002097:C-Reactive Protein; D005293:Ferritins; D005492:Folic Acid; D000469:Alkaline Phosphatase; D014805:Vitamin B 12