Vitamin B-12 and other B vitamins play a role in producing brain chemicals that affect mood and other brain functions. Low levels of B-12 and other B vitamins such as vitamin B-6 and folate may be linked to depression.
Low levels of a vitamin can result from eating a poor diet or not being able to absorb the vitamins you do consume. Older adults, vegetarians and people with digestive disorders such as celiac disease or Crohn's disease may have trouble getting enough B-12. Sometimes a vitamin B-12 deficiency occurs for unknown reasons. Your doctor may order a blood test to check levels of B-12 or other vitamins if a deficiency is suspected.
The best way to make sure you're getting enough B-12 and other vitamins is to eat a healthy diet that includes sources of essential nutrients. Vitamin B-12 is plentiful in animal products such as fish, meat, poultry, eggs and milk. Fortified breakfast cereals also are a good source of B-12 and other B vitamins.
Taking a daily supplement that includes vitamin B-12 may help your body get the nutrients it needs, especially if you're older than 50 or you're a vegetarian. However, B-12 and other vitamin supplements can interact with some medications and cause other concerns, especially in high doses. Talk to your doctor before you take a vitamin supplement.
Keep in mind, the role of B vitamins in depression isn't clear. If you have a vitamin deficiency, taking a supplement may help. But no supplement can replace proven depression treatments such as antidepressants and psychological counseling.