Vitamin B12

Vitamin B12 is essential for proper nerve development, red blood cell formation, and DNA synthesis. It works synergistically with folate — both are needed to prevent neural tube defects and support healthy cell division. B12 deficiency during pregnancy is associated with increased neural tube defect risk, low birth weight, and impaired fetal brain development. Vegetarians and vegans are at highest risk as B12 is found almost exclusively in animal products.

All pregnant women, but especially vegetarians, vegans, and those with poor absorption (older women, those with gastrointestinal conditions).

2.6 mcg daily (RDA during pregnancy) from food and supplements combined. Vegans often need 500–1,000 mcg supplemental B12 due to absorption issues.

Deficiency can develop slowly — B12 is stored in the liver. Supplement consistently throughout pregnancy.

Extremely safe — B12 is water-soluble and excess is excreted. No significant side effects at any reasonable dose.

Methylcobalamin is the most bioavailable form. If your prenatal vitamin contains cyanocobalamin, consider a separate methylcobalamin supplement.