Folate and vitamin B12 in relation to lactation: a 9-month postpartum follow-up study.
OBJECTIVE
To investigate the relation between lactation and markers of folate and vitamin B12 (B12) deficiency in women with and without vitamin supplementation.


METHODS
A 9-month follow-up study.


METHODS
Blood samples from 91 women, who gave birth to a single healthy child, were collected 3 weeks, 4 and 9 months postpartum and analysed for circulating level of homocysteine (tHcy), methylmalonic acid (MMA), folate and B12. The participants were categorized as exclusively, partly or not breast-feeding dependent on the degree of lactation 4 months postpartum. During follow-up, lifestyle factors were recorded by structured interviews.


RESULTS
Among 72 exclusively breast-feeding women, the median (10-90% percentile) tHcy was 5.8 (3.1-8.3) micromol/l 3 weeks postpartum, 6.1 (4.1-10.3) micromol/l 4 months postpartum and 5.3 (3.6-8.7) micromol/I 9 months postpartum. At 9 months postpartum, none of the women breast-fed exclusively. No significant change occurred in the concentration of B12 and folate. Exclusively breast-feeding women without vitamin supplementation had higher median tHcy than supplemented exclusively breast-feeding women 4 and 9 months postpartum (7.0 vs 5.4 micromol/l (P < 0.001) and 5.8 vs 4.5 micromol/l (P = 0.003), respectively). Six women had increased (>15 micromol/l) tHcy; four of these were unsupplemented and exclusively breast-feeding.


CONCLUSIONS
We found no overall indication of depletion of the folate and B12 stores during the lactation period in this population. However, folate-supplemented women had lower tHcy and higher folate levels, suggesting a beneficial effect of supplementation with folate throughout lactation.
Ramlau-Hansen
C H
CH
Institute of Public Health, Department of Health Science, Aarhus University, Arhus, Denmark. craha@as.aaa.dk
Møller
U K
UK
Henriksen
T B
TB
Nexø
E
E
Møller
J
J
D000328:Adult; D019587:Dietary Supplements; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage* / Q000097:blood*; D005494:Folic Acid Deficiency / Q000097:blood / Q000453:epidemiology; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007774:Lactation / Q000378:metabolism* / Q000502:physiology; D008019:Life Style; D008764:Methylmalonic Acid / Q000097:blood; D009751:Nutritional Requirements; D009752:Nutritional Status; D049590:Postpartum Period / Q000097:blood; D013997:Time Factors; D014805:Vitamin B 12 / Q000008:administration & dosage* / Q000097:blood*; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000453:epidemiology
D006710:Homocysteine; D008764:Methylmalonic Acid; D005492:Folic Acid; D014805:Vitamin B 12