A vitamin deficiency, or low levels of a vitamin in your blood, can be caused by diet or a malfunction in the way your body absorbs vitamins.

Vitamin B-12 is naturally found in animal products. That means people who follow a vegan or vegetarian diet may have trouble getting enough B-12. Some foods like cereal have B-12 added to them. That can help people who consume little or no animal protein get enough B-12. You can also take a vitamin supplement.

Some people consume enough B-12, but their bodies don’t properly absorb the vitamin. A B-12 deficiency can affect your health in various ways. Some have even linked depression to vitamin B deficiency.

Sources of B-12

B-vitamins, including vitamin B-12, have been linked to depression. But because depression is a complex condition, the connection isn’t fully understood.

Researchers in a 2005 article published in the Journal of Psychopharmacology reviewed studies of depression and low vitamin B-12 status. They found substantial evidence that a decrease in the vitamin B-12 serum correlates with an increase in depression. They also state that high vitamin B-12 status may be associated with better treatment outcome of depression. The researchers suggest people with depression take a 1-milligram supplement of B-12 daily. More research is needed to fully understand the link between B-12 and depression.

One possible connection is the effect of vitamin B-12 on the levels of serotonin in your brain, in addition to other chemicals. Serotonin helps to regulate your mood. Low levels of serotonin may be linked to depression. However, recent research has suggested that serotonin may play a smaller role in depression than previously thought.

If you’re experiencing depression, talk to your doctor. They can help you develop a treatment plan that’s right for you. Natural remedies, like a B-12 supplement, may help. But you’ll also likely need to participate in talk therapy and possibly take prescription medication.

Vitamin B-12 is also known as the energy vitamin. It helps keep your immune system healthy and your brain functioning. Some of the symptoms of a B-12 deficiency are similar to those of depression, which can make it difficult to identify a vitamin deficiency if you’re also depressed.

Depression symptomsVitamin B-12 deficiency symptoms
exhaustion or fatigue
rapid heartbeat without exercising
brain fog or difficulty concentrating
confusion or impaired thinking
lack of interest in activities you used to enjoy
trouble sleeping
increased or decreased appetite
unexplained body aches
feelings of guilt or anger

Some people are at an increased risk for vitamin B-12 deficiency. The highest sources of vitamin B-12 are animal products, like meat, fish, or diary. People who follow a vegetarian or vegan diet are at an increased risk for B-12 deficiency and may need to add a B-12 supplement to their daily diet. Some foods are fortified with B-12. So if you have a mostly plant-based diet, check food labels and pick grain products that are fortified with B-12.

You may also have an increased risk for vitamin B-12 deficiency if you:

  • recently had weight loss surgery, because the operation interferes with your body’s ability to extract B-12 from food
  • have been diagnosed with Crohn’s or celiac disease, conditions that can affect the way your body absorbs nutrients
  • are over the age of 50, because the stomach beings to produce less acid as you age, and this acid helps with B-12 absorption
  • take prescribed heartburn drugs, which reduce acid production in your stomach and may affect B-12 absorption

If you suspect you have a vitamin deficiency, make an appointment with your doctor. They can do a blood test to check the level of vitamins in your blood. You should also bring a list of the following to your appointment:

  • medications and supplements you take
  • symptoms you’ve experienced
  • questions for your doctor

Test results shouldn’t take more than a week to receive. If you find out you have a vitamin or nutrient deficiency, you can start implementing diet changes. Your doctor may also recommend temporarily taking supplements if the deficiency is severe.

If your blood work comes back normal, you can rule out a B-12 deficiency and look into other treatment options for depression.

Changes to your diet are the most effective way to treat a B-12 deficiency. If you aren’t vegan, add egg whites, poultry, and lean meat to your meals. Fish is an excellent source of B-12, so you should also try to regularly add fish to your diet. There are many types of fish, so if you don’t like one type, experiment with other varieties. Or use different cooking methods to change the taste.

Fish is easy to prepare. You can put a little olive oil, salt, pepper, and lemon on it and bake it in the oven. You can also put it on a grill or saute it in a frying pan with some butter and garlic.

Learn more: 11 best types of fish to eat »

You can also treat B-12 deficiencies by taking a B-12 supplement. Be sure to talk to your doctor first. Sometimes B vitamins can interact with medications, so your doctor may not recommend that you take them.

It’s also important to eat breakfast every day. Starting your day with fortified cereal and low-fat or fat-free milk is a great way to get some B-12 into your diet. And eating breakfast can help you feel more energized throughout the day.

Depression is a serious medical condition that can affect everything you do. While there may be a link between your B-12 levels and depression, it’s important to work with your doctor to come up with a holistic treatment plan that works for you.