Vitamin B12

Vitamin B12 (Cobalamin) is essential for DNA synthesis, red blood cell formation, neurological function, and methylation processes. Deficiency can lead to megaloblastic anemia, neurological damage (numbness, balance problems, cognitive impairment), and elevated homocysteine and MMA. Serum B12 reflects recent intake and circulating levels, but may not perfectly represent tissue stores, especially in the lower end of the normal range. Optimal levels for neurological health are often considered significantly higher than the lower limit of standard lab ranges (e.g., >400-500 pg/mL). Functional markers like MMA and homocysteine can help confirm status if serum B12 is borderline.