Vitamin B12 supports red blood cell formation, DNA production, nerve function, and energy metabolism, and too little can affect focus, mood, and heart health. It is also linked to bone strength, healthy skin and hair, and normal brain and eye function, so regular intake from food or supplements matters.
Essential Concepts: B12 supports blood, nerves, brain, bones, mood, and heart; deficiency can impair focus and health; food sources and supplements can help.