Is Vitamin B12 Safe in Breastfeeding

I am a breastfeeding mother and i want to know if it is safe to use Vitamin B12? Is Vitamin B12 safe for nursing mother and child? Does Vitamin B12 extracts into breast milk? Does Vitamin B12 has any long term or short term side effects on infants? Can Vitamin B12 influence milk supply or can Vitamin B12 decrease milk supply in lactating mothers?

Vitamin B12 exists naturally in milk at a concentration of 1 nanogram / mL (range: 0.3 to 3 ng / mL). Maternal supplementation with cyanocobalamin barely increases milk levels in well-nourished women (Sandberg 1981), but it does improve the levels in women of low socioeconomic status (Sneed 1981). The concentration in colostrum is up to 28 times higher than that of mature milk.The daily requirements for Vitamin B12 are 2.4 micrograms and increase to 2.8 micrograms daily during breastfeeding. Foods rich in vitamin B12 are meat, offal, eggs, dairy products, salmon, sardines, clams and fortified cereals. With a varied and balanced diet no vitamin supplements are needed, but B12 deficiency has been observed in the plasma and milk of women with strict vegetarian diets (vegans), malabsorptive diseases (eg, Crohn's disease, celiac disease), bariatric surgery, poor nutritional status, pernicious anemia, low socio-economic status and in cases of natural disasters or wars. There are numerous publications showing that infants of these mothers are at high risk of disease due to vitamin B12 deficiency, which can lead to anemia, stunting and psychomotor retardation. "Flash pasteurization" applied to breast milk of mothers who are HIV+ does not decrease vitamin B12 concentration. American Academy of Pediatrics: medication usually compatible with breastfeeding (AAP 2001).

Vitamin B12 is a normal component of human milk.[1] The recommended daily intake in lactating women is 2.8 mcg and for infants aged 6 months or less is 0.4 mcg.[2] Lactating mothers may need to supplement their diet to achieve the recommended daily intake or to correct a known deficiency. Low doses of vitamin B12 found in B complex or prenatal vitamins increase milk levels only slightly. Higher daily doses of 50 to 100 mcg or more are needed in cases of maternal deficiency. The breastfed infant is not exposed to excessive vitamin B12 in such cases, and their vitamin B12 status should improve if it was previously inadequate. Poor health outcomes in infants with vitamin B12 deficiency include anemia, abnormal skin and hair development, convulsions, failure to thrive, and mental developmental delay. One well-recognized at risk group are exclusively breastfed infants of mothers with B12 deficiency due to minimal or no dietary intake of animal products.[3][4][5][6][7][8][9] Infant vitamin B12 status can be improved through maternal B12 supplementation during pregnancy and lactation.[10][11][12][13] Deficient mothers who miss the opportunity to supplement during pregnancy should still be encouraged to supplement during early lactation since infant vitamin B12 status correlates with milk vitamin B12 levels in breastfed infants up to 6 months of age.[14][15][16][17] Although there are cases reported of exclusively breastfed infants with vitamin B12 deficiency having biochemical and clinical improvement through adequate maternal supplementation alone,[3] direct supplementation of the infant is recommended when such treatments are available.[18][19][8] Flash heat pasteurization of breastmilk does not reduce milk vitamin B12 concentration.[20]

Twelve exclusively breastfed infants between 4 and 11 months of age had biochemical, hematological and clinical findings consistent with vitamin B12 deficiency. Their mothers received a 50 mcg single dose of intramuscular vitamin B12. Within 5 to 8 days after the dose, the infants experienced significantly increased hemoglobin and reticulocyte counts, normoblastic erythropoiesis, improved mental status, regression of abnormal skin pigmentation, and reduction in tremors.[3] Three hundred sixty-six pregnant women in India received oral vitamin B12 50 mcg or placebo capsules once daily beginning during their first trimester of pregnancy and continuing until 6 weeks postpartum. Among 218 infants that underwent neurodevelopment testing at 30 months of age, those born to mothers randomized to vitamin B12 had higher expressive language scores than the placebo group when adjusted for baseline maternal vitamin B12 deficiency. Cognitive, receptive language and motor scores were not different between the two groups.[13]