Vitamin B12

What This Marker Means

Vitamin B12 supports nerve function, red blood cell production, and cognitive health. Low levels can cause fatigue, numbness, brain fog, or mood changes. Absorption decreases with age and poor nutrition.

How Alcohol Affects This Marker

Alcohol irritates the stomach lining and reduces B12 absorption. Poor dietary patterns around drinking further lower levels. Some people show normal serum B12 but have functional deficiency.

How to Discuss With Your Doctor

Ask whether your B12 level is truly adequate and if symptoms align with deficiency. If low-normal, ask about methylmalonic acid (MMA) testing for deeper insight.