Vitamin B12 deficiency symptoms and supplementation guidance clarified

Vitamin B12 deficiency affects roughly one in ten people in Germany and up to one in four people over 65, according to the German Family Insurance. Its symptoms overlap with iron deficiency—pale skin, fatigue, weakness—but also include distinct neurological signs such as tingling, numbness, reduced reflexes and gait disturbances, which can progress to severe anemia and cognitive impairment if untreated.

Supplementation of vitamin B12 can be administered daily or weekly because the vitamin is stored in the liver. The Federal Institute for Risk Assessment (BfR) recommends a maximum daily intake of 25 µg for healthy individuals aged 15 years and older, while higher doses (500–1000 µg) may be prescribed for diagnosed deficiencies. Various formulations are available, including tablets, capsules, lozenges, drops and even toothpaste. Absorption is biologically limited, so increasing the dose does not proportionally increase uptake.