Homocysteine nicotinic acid

Vitamin B12 and folate are both required for conversion of homocysteine to methionine. Increased serum homocysteine may help define vitamin B12 or folate deficiency. Homocysteine levels can also be elevated in vitamin Bg deficiency, renal failure, hypothyroidism, and in persons with a genetic defect in cystathionine /S-synthase. Additionally, elevated levels have been caused by medications including nicotinic acid, theophylline, methotrexate, and L-dopa. 

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