Depression is more common among people with vitamin B12 deficiency. Understanding how to increase your B12 intake can help reduce depressive symptoms.

Vitamin B12 plays a critical role in the production of dopamine and serotonin, neurotransmitters that help regulate your mood.

When you don’t get enough B12 in your diet, or your body doesn’t process it correctly, it can lead to mental health symptoms, such as depression, irritability, or anxiety.

2020 research suggests that vitamin B12, also known as cobalamin, may be helpful in improving mood and reducing symptoms of depression in some people.

It’s well-known that a deficiency in vitamin B12 can result in neurological and psychiatric problems, including depression, irritability, and memory loss.

Vitamin B12 deficiency leads to higher levels of an amino acid known as homocysteine. A large 2017 study in Taiwan indicates that high levels of homocysteine have been associated with a higher risk of depression, as well as other health issues such as heart disease and stroke.

One study tested the link between depression and serum vitamin B12 levels in 89 participants (mostly children and adolescents). The findings showed that severe depressive symptoms were linked to lower levels of vitamin B12.

The researchers conclude that a deficiency of vitamin B12, or even low-normal levels, may be a significant contributing factor toward depression.

Types of vitamin B

B vitamins are important for supporting overall brain and mental health by supporting energy production, healthy brain function, and the production of neurotransmitters that regulate mood.

Here are the 8 B vitamins:

  • Thiamin (B1): Thiamin helps convert food into energy and supports healthy nerve function.
  • Riboflavin (B2): Riboflavin supports energy production and antioxidant activity.
  • Niacin (B3): Niacin helps produce energy and supports healthy brain function.
  • Pantothenic acid (B5): Pantothenic acid helps the body convert food into energy and supports healthy adrenal function.
  • Pyridoxine (B6): Vitamin B6 supports brain development and function, as well as the production of neurotransmitters that regulate mood.
  • Biotin (B7): Biotin supports healthy skin, hair, and nails, as well as energy production.
  • Folate (B9): Folate helps produce and maintain healthy cells, including brain cells.
  • Cobalamin (B12): B12 plays a role in red blood cell production and the synthesis of neurotransmitters such as serotonin and dopamine, which are important for regulating mood and emotions.

Natural sources of B12

Since your body doesn’t make vitamin B12, it’s important to get enough in your diet.

Here are some food sources of vitamin B12:

  • clams
  • liver (beef or chicken)
  • fish (salmon, trout, tuna, sardines)
  • meat (beef, pork, lamb)
  • poultry (chicken, turkey)
  • eggs
  • dairy products (milk, cheese, yogurt)
  • fortified plant-based milks and cereals
  • nutritional yeast

Low levels of vitamin B12 can lead to a range of neurological symptoms, including depression, anxiety, and mood swings. In severe cases, a vitamin B12 deficiency can cause more serious symptoms such as confusion, memory loss, and even psychosis.

Here are some common symptoms of vitamin B12 deficiency:

  • fatigue and weakness
  • pale skin
  • rapid heartbeat and breathing
  • shortness of breath
  • dizziness or lightheadedness
  • constipation, diarrhea, or other digestive issues
  • loss of appetite and weight loss
  • numbness or tingling in the hands and feet
  • muscle weakness or stiffness
  • difficulty walking or balancing
  • memory loss or cognitive impairment
  • depression, anxiety, irritability, or other mood changes

Risk factors for vitamin B12 deficiency

There are several risk factors that can contribute to a deficiency in vitamin B12, including:

  • A diet lacking in vitamin B12-rich foods, such as meat, fish, and dairy products.
  • Gastrointestinal (GI) disorders that affect the absorption of vitamin B12, such as celiac disease, Crohn’s disease, or atrophic gastritis.
  • Surgery that involves the removal of part of the stomach or small intestine.
  • Heavy alcohol consumption, which can interfere with the absorption and storage of vitamin B12.
  • Aging, as the body’s ability to absorb and utilize vitamin B12 may decrease with age.
  • Vegetarian or vegan diets that do not include any animal products and may require supplementation to ensure adequate intake of vitamin B12.
  • Pernicious anemia, which is an autoimmune condition that affects the body’s ability to absorb vitamin B12
  • Certain medications that can interfere with the absorption of vitamin B12, such as metformin, proton pump inhibitors, and H2 blockers.

Your vitamin B12 levels can be tested through a blood test taken at your doctor’s office or lab.

Low vitamin B12 levels are those that fall below the “normal” range of 200 to 900 pg/mL (picograms per milliliter). If your B12 levels are low, further testing may be needed to determine the underlying cause of the deficiency.

Treatment for vitamin B12 deficiency typically involves vitamin B12 supplementation. The method of supplementation can vary depending on the severity of the deficiency and the underlying cause. Here are some common methods of treatment:

  • Vitamin B12 injections: Injections may be given for severe B12 deficiency. These intramuscular injections are typically given once a week for several weeks until the body’s vitamin B12 stores are replenished. After that, injections may be given less frequently to maintain adequate levels.
  • Oral supplements: These supplements are available in various forms, such as tablets, capsules, and lozenges. The recommended dosage and duration of treatment will depend on your needs and the severity of the deficiency.
  • Nasal spray: A vitamin B12 nasal spray is also available for those who can’t tolerate injections or oral supplements.

A review found that supplementing with vitamin B12 early enough can delay the onset of depression and also improve the effects of antidepressants.

If you’re diagnosed with depression, you may also be treated with a combination of medication, psychotherapy, and lifestyle changes.

Can you take vitamin B12 with antidepressants?

Yes, it’s generally safe to take vitamin B12 with antidepressants, and some evidence suggests they may enhance the effectiveness of antidepressant medications.

One study of 153 participants found that B12, folic acid, and B6 supplements enhanced and sustained antidepressant response over the one-year mark.

But it’s important to note that some medications can interact with supplements and cause unwanted side effects or affect the way the medication works in your body. So, be sure to consult your healthcare provider before starting any supplements.

Supplementing with vitamin B12 may help address deficiencies and support healthy nerve and brain function, potentially leading to improved mental health outcomes.

If you’re experiencing depression, consider reaching out to a healthcare professional who can help you get started on the right treatment.