Vitamin B12
Vitamin B12 (cobalamin) is essential for red blood cell formation, neurological function, and energy release from food. It is found primarily in animal products (meat, fish, dairy, eggs).
Relationship to Thyroid Disease
- A meta-analysis found significantly lower B12 levels in people with hypothyroidism (but not hyperthyroidism or subclinical hypothyroidism) compared to healthy individuals.
- B12 deficiency in autoimmune thyroid disease is often secondary to pernicious anaemia — an autoimmune condition that prevents B12 absorption.
- No substantial evidence that B12 supplementation improves thyroid function.