| Study design |
Results |
Conclusion and Limitation |
| Hellegers A et al. [7] |
Pregnant (n=31) and non-
pregnant women (n=29), were stratified into three supplementation groups, 250, 500 and 1000 µg B12/d (oral dose). Serum B12 concentrations were measured 1, 1.5 and 3 h later. Responder was defined as >160 µg increase observed in serum B12 concentration. |
None of the women in either the pregnant or non-pregnant group showed any response to the 250 µg supplement. Pregnant women supplemented with 1000 µg had an 88.8% increase in serum B12 while non-pregnant women had a 28.5% increase. |
Compared to non –pregnant women absorption of vitamin B12 is significantly increased in pregnancy.
Serum B12 was the only response measured. |
| Eneroth H et al. [83] |
| RCT in Bangladesh, n=4436 (GW≥14). Daily micronutrient supplements either: 1)folic acid and 30 mg iron; Fe30Fol or 2) folic acid and 60 mg iron; or 3) a multiple micronutrient including folic acid and 30 mg iron (MMS). Supplementation continued up to 3 mo postpartum. |
46% (n=670) of women had low B12 status, At 6 mo prevalence of infant B12 deficiency significantly lower in the MMS group than in the Fe30Fol group (26.1 vs. 36.5%) . |
B12 deficiency highly prevalent in this population; MMS may have a beneficial effect on B12 status in infancy.
Small effect size; B12 was the only response measured; No assay of newborn B12 status. |
| Baylin A et al. [84] |
| RCT in Tanzania. HIV-infected mothers (n=716); daily oral dose of one of four regimens: vitamin A, multivitamins (B including 50 µg B12, C, E), multivitamins including A, or placebo. Supplementation started at first prenatal visit and continued up to 6 mo postpartum. |
Compared to infants from non-multivitamin-supplemented mothers, multivitamins increased B12 at 6 wk and 6 mo (mean differences=176 pmol/L, and 127 pmol/L, respectively), significant reductions in the prevalence of B12 deficiency at 6 mo. |
Multivitamin (B, C, E) supplementation had major effect on serum B12 at 6 wk that was sustained through 6 mo of age.
B12 was the only response measured;
no information on breast feeding frequency; complementary feeding. |
| Duggan C [85] |
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| RCT in India. Pregnant women (<14 GW) randomized to receive either an oral B12 (50 μg/day) or placebo through 6 wk postpartum. |
Compared to the placebo group, supplemented women had higher median plasma B12 concentrations at both the 2nd (216 vs. 111 pmol/L) and 3rd (184 vs. 105 pmol/L) trimesters; higher breast milk B12 (136 vs. 87 pmol/L) in the placebo group; higher infant plasma B12 (199 vs. 136 pmol/L); reduced infant MMA and tHcy |
Oral maternal vitamin B12 supplementation is effective to improve maternal and infant B12 status.
HoloTC was not assayed; data were not available for women after postpartum; too short follow-up period for infants B12 status. |
| Monsen et al. [86] |
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| RCT in Norway. n=107 infants (6 wk) randomized to receive either an intramuscular injection of B12 (400 μg) or no intervention (control). Biomarkers were assayed at enrollment and at age 4 mo. |
Compared to the control group supplement-treated infants had 75% higher median serum B12, raised serum B12 (IQR: 291–497 pmol/L), and lowered MMA (from 0.58 to 0.20 μmol/L) and tHcy (from 7.46 to 4.57 μmol/L) at 4 mo. |
Supplementation can normalize a metabolic profile consistent with impaired B12 status in young infants.
Control group did not receive placebo medication; effect on neurological
parameters were not assessed. |
| Torsvik et al. [87] |
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| RCT, infants (n=79, <8 mo, plasma tHcy concentration ≥6.5 μmol/L ) ) randomized to either an intramuscular injection of B12 (400 μg) or a sham injection |
Supplementation decreased plasma tHcy by 54%, and MMA by 84%, no significant changes in the placebo group.
Sig. higher motor function [Alberta Infants Motor Scale (AIMS)] score in the B12 group than in the placebo group (7.0 (5.0, 9.0) vs. 4.5 (3.3, 6.0)]. Higher proportion showed improvements in regurgitations (69% vs. 29%, respectively; P=0.003). |
In infants with impaired B12 function, 400 μg intramuscular injection of B12 resulted in biochemical evidence of repletion and improvement in motor function and regurgitations;
too short follow-up period (1 mo). |
| 1RCT indicates randomized controlled trial. |
