The Benefits of B Complex Vitamins

Why are they important and what are the food sources?

Healthy B vitamin rich foods
Maximilian Stock Ltd./Getty Images

A B complex vitamin usually delivers eight of the B vitamins: B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folic acid), and B12 (cobalamin). Found naturally in meat, leafy greens, dairy, beans, peas, and whole or fortified grains, B complex vitamins help your body make energy from the food you eat and form red blood cells.

Uses for B Complex Vitamins

With a key role in converting food into fuel, proponents claim that B complex vitamins can help with a variety of conditions, including anxietydepressionheart disease, and premenstrual syndrome (PMS).

In addition, some people take a vitamin B complex to increase energy, enhance mood, improve memory, boost skin and hair health, and stimulate the immune system.

While most people who eat a varied diet get enough B vitamins from food, some people are at an increased risk of deficiency, particularly those who are over the age of 50, take antacid medication, or have celiac disease, Crohn's disease, gastritis, or other digestive disorders.

If you have had stomach or weight loss surgery, drink alcohol regularly, or follow a vegetarian or vegan diet, you may be more prone to a deficiency.

Pregnant and breastfeeding women may need more vitamins B6, B12, and folic acid.

The Benefits of B Complex Vitamins

Each B vitamin is essential to certain bodily functions:

  • B1 (Thiamine): Vitamin B1 helps the body make new cells.
  • B2 (Riboflavin): This B vitamin is important for red blood cell production and fighting free radicals.
  • B3 (Niacin): Helps regulate the nervous and digestive systems and aids in the conversion of food into energy.
  • B5 (Pantothenic acid): Breaks down fats and carbohydrates for energy and is responsible for the production of hormones.
  • B6 (Pyridoxine): Helps the body turn food into energy. Vitamin B6 also helps the body fight infection.
  • B7 (Biotin): Involved in the production of hormones.
  • B9 (Folic acid): This B vitamin helps cells make and maintain DNA and promotes the growth of red blood cells. It also helps to reduce the risk of birth defects.
  • B12 (Cobalamin): Vitamin B12 helps regulate the nervous system and plays a role in red blood cell formation.

Food Sources of B Complex Vitamins

To boost your intake of B vitamins, look for the following foods:

  • B1 (thiamine): Whole grain foods such as bread, breakfast cereals, rice, noodles, and flour, wheat germ, eggs, beans, and nuts.
  • B2 (riboflavin): Milk and dairy products, nuts, eggs, green leafy vegetables, lean meats, legumes, and milk.
  • B3 (niacin): Eggs, fish, nuts, dairy, lean meats, legumes, and yeast.
  • B5 (pantothenic acid): Vitamin B5 is found in almost all foods, including avocados, broccoli, kale, whole grains, potatoes, eggs, legumes, and meat.
  • B6 (pyridoxine): Potatoes, chickpeas, fruits (except citrus), chicken, fish, and organ meats.
  • B7 (biotin): Wheat germ, whole grain foods, egg yolks, fish, milk, mushrooms, nuts, Swiss chard, chicken, and salmon.
  • B9 (folate): Beef liver, spinach, beans and legumes, asparagus. orange juice, broccoli, peanuts, avocado, dark leafy greens, and salmon.
  • B12 (cobalamin): Fish, beef, milk, yogurt, cheese, eggs, shellfish, beef liver, and clams.

Possible Side Effects

Although B complex supplements are water-soluble and do not stay in the body for long, large doses of the vitamins in supplement form can cause certain side effects:

B3 (niacin): Skin flushing or pain, elevated blood sugar levels, and liver toxicity.

B6 (pyridoxine): Nerve damage, skin lesions, worsening of kidney function, and increased risk of heart attack, stroke and death in people with diabetes and advanced kidney disease.

B9 (folic acid): Kidney damage, increased insulin resistance in offspring, lower natural killer cell activity in older women, and may be associated with increased risk of some cancers.

Can mask the diagnosis of a vitamin B12 deficiency.

B12 (cobalamin): Acne and rosacea in some people.

There is a daily tolerable intake level (UL) for each B vitamin, which is above what most people need. Getting more than the UL increases your chances of side effects.

A Word From Verywell

To stay healthy, most people can get what they need by eating a varied, balanced diet filled with delicious foods naturally rich in B vitamins, such as leafy greens, nuts, beans and legumes, whole grains, lean protein, and eggs. There isn't solid evidence to support taking excessive amounts of B vitamins if you're not deficient in them.

If you're not getting enough B vitamins from your diet, taking B complex vitamins may be beneficial for some people. Deficiency in B vitamins can cause a number of symptoms, including tiredness, anemia, loss of appetite, depression, abdominal pain, muscle cramps, hair loss, and eczema.

Just be sure to consult your health care provider to find out whether a B complex supplement is right for you (and if so, the appropriate amount considering the total daily amount you are getting from food and supplements).


Afriyie-Gyawu E, Ifebi E, Ampofo-Yeboah A, Kyte B, Shrestha S, Zhang J. Serum folate levels and fatality among diabetic adults: A 15-y follow-up study of a national cohort. Nutrition. 2016 Apr;32(4):468-73. 

Kim SJ, Zuchniak A, Sohn KJ, et al. Plasma folate, vitamin B-6, and vitamin B-12 and breast cancer risk in BRCA1- and BRCA2-mutation carriers: a prospective study. Am J Clin Nutr. 2016 Sep;104(3):671-7. 

Tio M, Andrici J, Cox MR, Eslick GD. Folate intake and the risk of prostate cancer: a systematic review and meta-analysis. Prostate Cancer Prostatic Dis. 2014 Sep;17(3):213-9. 

Wang R, Zheng Y, Huang JY, Zhang AQ, Zhou YH, Wang JN. Folate intake, serum folate levels, and prostate cancer risk: a meta-analysis of prospective studies. BMC Public Health. 2014 Dec 29;14:1326.

Disclaimer: The information contained on this site is intended for educational purposes only and is not a substitute for advice, diagnosis or treatment by a licensed physician. It is not meant to cover all possible precautions, drug interactions, circumstances or adverse effects. You should seek prompt medical care for any health issues and consult your doctor before using alternative medicine or making a change to your regimen.

Continue Reading