Vitamin B12-Check

Serum vitamin B12 measurement for deficiency screening. At €14.57 (plus blood draw), a targeted test for vegetarians, vegans, older adults, and metformin users — the groups at highest risk of B12 depletion.

Vitamin B12 (cobalamin) is essential for DNA synthesis, red blood cell formation, myelin sheath maintenance, and methylation reactions. Unlike most water-soluble vitamins, B12 has substantial liver stores (2–5 years' supply), meaning deficiency develops slowly but can cause irreversible neurological damage if undetected. B12 is found exclusively in animal products — meat, fish, dairy, and eggs. Strict vegans have a near-100% probability of developing deficiency without supplementation. Vegetarians are at intermediate risk depending on dairy and egg intake. Older adults frequently develop deficiency due to declining gastric acid production (required for B12 absorption from food). Metformin, proton pump inhibitors, and H2 blockers also reduce B12 absorption. Neurological symptoms of B12 deficiency include peripheral neuropathy (tingling, numbness), cognitive impairment, depression, and balance problems. These can precede haematological changes (macrocytic anaemia) by years. Early detection through routine screening is therefore important in at-risk groups. Serum B12 below 200 pg/mL indicates likely deficiency; 200–300 pg/mL is a grey zone where functional markers (methylmalonic acid, homocysteine) provide additional diagnostic clarity. Mein Labor Leipzig can test homocysteine as part of expanded profiles. A single B12 test is sufficient for initial screening. If deficiency is confirmed and supplementation started, recheck after 3–6 months.