Vitamin B complex is composed of eight B vitamins:

Each of these essential vitamins contributes to your overall bodily function. Read on to learn more about how these nutrients benefit you, how much you need, whether you should take supplements, and more.

B vitamins play a vital role in maintaining good health and well-being. As the building blocks of a healthy body, B vitamins have a direct impact on your energy levels, brain function, and cell metabolism.

Vitamin B complex helps prevent infections and helps support or promote:

  • cell health
  • growth of red blood cells
  • energy levels
  • good eyesight
  • healthy brain function
  • good digestion
  • healthy appetite
  • proper nerve function
  • hormones and cholesterol production
  • cardiovascular health
  • muscle tone

In women

B vitamins are especially important for women who are pregnant and breastfeeding. These vitamins aid in fetal brain development as well as reduce the risk of birth defects.

And for expectant mothers, B vitamins may boost energy levels, ease nausea, and lower the risk of developing preeclampsia.

In men

B vitamins are thought to increase testosterone levels in men, which naturally decrease with age. They may also help men build muscle and increase strength. However, human studies confirming these claims are lacking.

The recommended daily amount of each B vitamin varies.

For women, the recommended daily intake is:

For men, the recommended daily intake is:

Older adults and women who are pregnant require higher amounts of B vitamins. Your doctor can provide dosage information tailored to your individual needs.

Certain underlying health conditions can prevent your body from properly absorbing vitamin B. You should also talk to your doctor about your vitamin B intake if you have:

Most people get enough B vitamins by eating a balanced diet. However, it’s still possible to be deficient.

The following symptoms may be a sign that you’re not getting enough B vitamins:

  • skin rashes
  • cracks around the mouth
  • scaly skin on the lips
  • swollen tongue
  • fatigue
  • weakness
  • anemia
  • confusion
  • irritability or depression
  • nausea
  • abdominal cramps
  • diarrhea
  • constipation
  • numbness or tingling in the feet and hands

If you’re experiencing any of these symptoms and aren’t sure why, make an appointment to see your doctor.

Although it’s possible that you’re experiencing a vitamin B deficiency, these symptoms also overlap with many other underlying conditions. Your doctor can make a diagnosis and advise you on any next steps.

If you’re deficient in B vitamins you may experience a range of symptoms depending on which B vitamins you’re lacking.

If left untreated, deficiency could increase your risk of developing:

Vitamin B-12 deficiency, in particular, may increase your risk of neuropsychiatric disorders. Researchers are also investigating its role in hyperhomocysteinemia and atherosclerosis.

Babies born to women who were deficient in folic acid during pregnancy are more likely to have birth defects.

Lots of foods contain B vitamins, which makes it easy to get enough from your diet. It’s best to get your B vitamins from a wide variety of food sources. This helps to ensure you’re getting enough of each type.

You can find vitamin B in:

  • milk
  • cheese
  • eggs
  • liver and kidney
  • meat, such as chicken and red meat
  • fish, such as tuna, mackerel, and salmon
  • shellfish, such as oysters and clams
  • dark green vegetables, such as spinach and kale
  • vegetables, such as beets, avocados, and potatoes
  • whole grains and cereals
  • beans, such as kidney beans, black beans, and chickpeas
  • nuts and seeds
  • fruits, such as citrus, banana, and watermelon
  • soy products, such as soy milk and tempeh
  • blackstrap molasses
  • wheat germ
  • yeast and nutritional yeast

If your doctor has recommended that you increase your intake of a specific B vitamin, check out these curated food lists:

Most people get enough B vitamins through their diet. Your diet is also the best way for your body to get these vitamins.

You shouldn’t take a supplement unless your doctor has confirmed that you’re deficient in a specific B vitamin. They’ll tell you whether you should take a specific B supplement or add a vitamin B complex supplement to your routine.

You may be more likely to need supplementation if you:

  • are age 50 or older
  • are pregnant
  • have certain chronic health conditions
  • eat a vegetarian diet
  • eat a vegan diet

Supplements are available over the counter at your local pharmacy or health food store.

Supplements aren’t regulated by the U.S. Food and Drug Administration, so you should only buy from a trusted, reputable brand. This helps to ensure you’re taking a high-quality product without any questionable additives. Your doctor may be able to recommend a specific brand to consider.

You should always read all labels carefully and follow any directions given by the manufacturer. If you have questions about the dosage, talk to your doctor.

You’re unlikely to get too much vitamin B complex from your diet. That’s because B complex vitamins are water soluble. That means they aren’t stored in your body but are excreted in your urine daily.

You’re also unlikely to get too much vitamin B if you’re taking any supplementation as directed.

That said, overdose is possible — especially if you’re taking a supplement without receiving a deficiency diagnosis from your doctor.

Symptoms of a vitamin B complex overdose include:

  • excessive thirst
  • skin conditions
  • blurry vision
  • abdominal cramps
  • nausea
  • vomiting
  • increased urination
  • diarrhea
  • skin flushing

Seek immediate medical attention if you think you’re experiencing symptoms of a vitamin B complex overdose.

You should also check in with your doctor if you’ve been taking supplements without having a diagnosed deficiency. Taking too much vitamin B complex long-term can lead to nerve damage. This could result in losing control of your bodily movements.

Always talk to your doctor before you add any supplements to your routine.

You can discuss your desired health goal and why you think supplementation is necessary. Your doctor can help you determine if this is the best treatment option and advise you on any next steps.

Some supplements can interact with certain underlying conditions and medications, so it’s important to keep your doctor informed.

You should also see your doctor if you think you may be deficient in B vitamins. They can help determine what’s causing your symptoms and, if needed, recommend ways to increase your B vitamin intake.