# Vitamin B12 nutritional requirements and deficiency risks > Live situation record from CLSTR: https://clstr.news/situations/vitamin-b12-nutritional-requirements-and-deficiency-risks > Updated: 2026-08-26T08:52:00.000Z. Sources: 2. Developments: 2. Vitamin B12 is identified as a critical nutrient for DNA synthesis, red blood cell production, and the maintenance of the nervous system, specifically the myelin sheath. Deficiencies can result in anemia, neurological issues such as numbness, fatigue, and cognitive difficulties. Because the nutrient is found almost exclusively in animal products, individuals following vegan or restrictive diets are at a higher risk of deficiency. While the German Nutrition Society (DGE) suggests that vegans and vegetarians rely on fortified foods and supplements to meet specific daily requirements, data from the National Institutes of Health highlights natural concentrated sources such as beef liver, clams, oysters, salmon, and dairy. Other factors affecting B12 levels include digestive disorders, certain medications for gastric acidity, alcohol consumption, and the use of oral contraceptives. While deficiency symptoms may take months or years to appear due to liver stores, there is an increasing observation of deficiency in young adults aged 18-34 who follow diets low in animal products. ## Timeline ### 2026-08-26: Vitamin B12 importance and dietary sources Vitamin B12 is vital for neurological health and red blood cell production. Deficiencies, common in those with limited animal product intake, can cause anemia and nerve issues. Key sources include liver and sea 2 sources. https://clstr.news/cluster/vitamin-b12-importance-and-dietary-sources ### 2026-08-16: Vitamin B12 requirements for vegan and vegetarian diets Vitamin B12 is essential for nerve and blood health. Experts recommend that vegans and vegetarians use supplements or fortified foods to prevent deficiency, as reliable plant-based sources are scarce. 2 sources. https://clstr.news/cluster/vitamin-b12-requirements-for-vegan-and-vegetarian-diets --- Cite as: Vitamin B12 nutritional requirements and deficiency risks. CLSTR, https://clstr.news/situations/vitamin-b12-nutritional-requirements-and-deficiency-risks