Vitamins

Vitamin B12

Critical for nerves and blood cells, absorption drops with age.

Vitamin B12 is essential for nerve myelination, red blood cell formation, and DNA synthesis. Deficiency causes irreversible neurological damage if untreated. Absorption decreases significantly with age due to declining stomach acid production. Up to 43% of older adults have low or marginal B12 status, making it one of the most common nutrient deficiencies in aging populations.

Dosage

RDA: 2.4mcg for adults

Optimal for longevity: Longevity-focused practitioners often target serum B12 above 500 pg/mL, requiring 500-1,000mcg supplementation for older adults.

Deficiency signs

~6% of adults under 60 and ~20% of adults over 60 are B12 deficient in the US

  • Tingling or numbness in hands and feet
  • Fatigue and weakness
  • Difficulty with balance
  • Memory problems or confusion
  • Sore, swollen tongue

Top food sources

Clams (3 oz)84mcg
Beef liver (3 oz)70.7mcg
Nutritional yeast (1 tbsp)2.4mcg
Wild salmon (3 oz)4.8mcg
Tuna (3 oz)2.5mcg

Research

Allen LH (2009). How common is vitamin B-12 deficiency? American Journal of Clinical Nutrition, 89(2), 693S-696S.

Track your vitamin b12 intake

Biohack logs vitamin b12 alongside 22 other longevity nutrients in every meal.

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