Older adults: As you age, your power to absorb vitamin B12 decreases and your appetite declines, rendering it difficult to get enough B12 through diet alone.
Vegetarians/ Vegans: Vitamin B12 is naturally found in animal products like meat, dairy, eggs and seafood. Vegans and strict vegetarians could be prone to developing a B12 deficiency if they don’t really get enough of the vitamin through fortified foods or supplements.
People taking certain medications: Commonly prescribed medications can cause a deficiency in B vitamins. For example, proton pump inhibitors, which are medications that lower stomach acid, can decrease the absorption of B12, while metformin, a well known diabetes drug, can decrease quantities of both B12 and folate. Birth control pills may also deplete several B vitamins, including B6, B12, folate and riboflavin.
People with certain medical conditions: People who have certain medical conditions, such as celiac disease, cancer, Crohn’s disease, alcoholism, hypothyroidism and anorexia, are more vulnerable to developing nutrient deficiencies, including B vitamins.