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Nutritional
Vitamin B12
Essential for nerve function, DNA synthesis, and red blood cell formation — deficiency is common, especially after age 50.
Optimal Range
> 500 pg/mL (optimal) · 200-900 pg/mL (lab range)
Why It Matters
B12 deficiency causes irreversible nerve damage if left untreated and is associated with elevated homocysteine, cognitive decline, and anemia. Absorption decreases with age and with use of common medications like metformin and PPIs.