Even for lacto-vegetarians, food sources alone often fall short of the higher requirements during pregnancy and breastfeeding, making supplementation the safer approach during these stages.
Serious side effects are extremely uncommon , especially with intramuscular (IM) and IV administration using clinically appropriate doses
The body can do this but many times the reason the deficiency exists is because there is some venerability with formation of methyldonors (like methylcobalmin)
These substances may affect hormone production, which can throw off your monthly menses
The investigations on in vitro BBB or BCB models, analogous to those published by Mller et al
Patlakas G, Bouros D, Tsantekidou-Pozova S, Koukourakis MI