The best way to avoid developing a B12 deficiency is to add certain foods to your diet. The best dietary sources of vitamin B12 include animal products, and some fortified breakfast

cereals.56. All adults need around 1.5mcg of vitamin B12 every single day. Most people that eat meat products should be able to get enough B12 in their diet. But those that follow a vegan

diet may be at risk of a deficiency, warned the NHS.