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Everything You Need to Know About B-Complex Vitamins

Reading Time: 5 minutes 33 seconds


Date: 2022-02-11T00:00:00-05:00

If you are interested in nutrition or supplements, you’ve heard of the B-complex vitamins. This group of eight micronutrients is responsible for everything from repairing DNA to accessing the energy in foods.

Vitamins are essential micronutrients. You only need them in small quantities, but they play significant roles in everyday functioning. Deficiencies can cause symptoms and illness.

A well-rounded diet in whole foods should provide plenty of B vitamins, but some people have gaps in their diets. Learn more about these crucial nutrients and how to ensure you and your clients get enough of the B complex.

What Are B-Complex Vitamins?

Also known as the vitamin B complex, this is a group of eight water-soluble vitamins necessary for normal functioning:

  • Vitamin B1 (thiamine)

  • Vitamin B2 (riboflavin)

  • Vitamin B3 (niacin)

  • Vitamin B5 (pantothenic acid)

  • Vitamin B6 (pyridoxine)

  • Vitamin B7 (biotin)

  • Vitamin B9 (folic acid, folate)

  • Vitamin B12 (cobalamin)

Despite the similarity in naming, the B vitamins are not related. The B-vitamin complex lists all the essential water-soluble vitamins, except for C. Because they are water-soluble, excess quantities are excreted in the urine.

Check out this ISSA blog to learn about the crucial role all vitamins play in the body.

Why Do We Need B-Complex Vitamins?

Each of these vitamins has its role in optimal health. You need them to get energy from food, produce red blood cells, for optimal brain function and nerve health, repair DNA, produce hormones, and more.

Can You Be Deficient in B Vitamins?

Yes, it is possible to be deficient in one or more B vitamins, although most B deficiencies are uncommon in Western diets. Older adults, pregnant women, and people with certain medical conditions, like alcohol use disorder or Crohn’s disease, are more at risk for deficiencies.

B12 deficiency is the most common type and can lead to a type of anemia that causes nerve problems and tingling sensations, heart palpitations, depression, memory problems, and pale skin. Vegetarians and vegans are vulnerable to this deficiency because B12 is primarily found in meats and dairy products.

What You Need to Know About Each B Vitamin

The B vitamins ended up with similar names because, at one time, experts believed it was a single substance. As science evolved, it became clear that several compounds were at work. Each one is different and not necessarily related to the other. All play a crucial role in health and normal functioning.


Thiamine is essential for healthy cell growth and function and healthy organs, especially the heart and brain. Women and men need 1.1 and 1.2 mg of thiamine daily. Pregnant and lactating women should have 1.4 mg. Look for thiamine in fortified grains, fish, pork, lentils, beans, yogurt, and sunflower seeds.


You need riboflavin for cell growth, to produce energy, and to break down fats and medications. Recommended daily amounts are 1.1 mg for women, 1.4 mg for pregnant women, and 1.3 mg for men. Riboflavin is in dairy, eggs, meat, salmon, chicken, fortified grains, almonds, and leafy greens.


Niacin supports the functions of hundreds of enzymes in the body, playing a role in energy conversion, DNA repair, antioxidant action, the creation of cholesterol, and more. Aim for 16 mg per day for men, 14 mg for women, and 18 mg for pregnant women.

Vitamin B5

B5 also works with enzymes to break down fatty acids and build other fats. It plays a vital role in metabolism. Adult men and women should get 5 mg per day, while pregnant women need 6 mg. You can get B5 from fortified food (such as grains), chicken, dairy, potatoes, eggs, broccoli, oats, brown rice, avocados, nuts, and seeds.

Vitamin B6

Vitamin B6 assists in the breakdown of all the macronutrients (proteins, carbohydrates, and fats), supports immune system function, and regulates homocysteine levels, which is essential for heart health. Most men should get 1.3 mg per day, women 1.2 mg, and pregnant women 1.9 mg. Good sources of B6 include tuna salmon, poultry, leafy greens, oranges, cantaloupe, and fortified grains.

Vitamin B7

B7 is also necessary for metabolizing the macronutrients. It regulates signals between cells and gene activity. All men and women should get 30 micrograms of B7 daily. You can get it from eating eggs, salmon, pork, avocado, nuts and seeds, and sweet potatoes.

Folic Acid

Everyone needs folic acid for healthy homocysteine levels and producing red blood cells. It is essential during rapid growth, so pregnant women need to be very careful about folic acid intake. In general, men and women should consume about 400 micrograms per day, while pregnant women need 600 micrograms. Folic acid is found in beans, leafy greens, sunflower seeds, peanuts, fruit, whole grains, eggs, seafood, and liver.

Vitamin B12

Vitamin B12 is necessary for making new red blood cells and for the healthy functioning of nerves and the brain. Men and women should aim for about 2.4 micrograms per day and pregnant women 2.6 micrograms. B12 is mainly found in meat, poultry, fish and shellfish, eggs, and dairy. Non-animal sources include fortified or enriched milk substitutes, grains, and nutritional yeast.

Women and men have different dietary needs. Read this ISSA blog to learn more about macro and micronutrients for women.** **

Who Needs a B-Complex Supplement?

Visit the supplement aisle at the pharmacy, and you’ll see a range of vitamin B products, from individual vitamins to the entire B-complex in one pill. Does anyone really need these supplements, or is diet enough?

A Healthy Diet is Adequate for Most

A varied, healthy diet is enough for adequate vitamin B intake for most people. Most deficiencies are rare in the modern Western diet. If you eat whole and fortified grains, low-fat dairy, lean meats, fish, and poultry, and plenty of fresh vegetables and fruits, you probably don’t need a B-complex supplement.

Pregnant and Lactating Women

Pregnant and lactating women generally need more of all the micronutrients. Folic acid is essential for healthy fetal development. Women should talk to their doctors about supplements, but most prenatal vitamins contain all the B vitamins necessary to make up for dietary deficiencies.


If you don’t eat any animal products, a vitamin B12 deficiency can be an issue. If you have a client interested in plant-based eating, make sure they talk to their doctor about supplementation. Vegans can get B12 through supplements, nutritional yeast, and fortified products like grains.

B-Complex Vitamins for Fitness

There are many reasons B vitamins may be even more essential for active people. They help create new red blood cells, necessary for repairing muscle tissue after a workout. And, of course, they fuel workouts because of their role in getting energy out of food.

But does this mean you need vitamin B supplements if you work out a lot? The only real reason to supplement is if you have a poor diet, certain nutritional gaps, such as not eating animal products, or if you have a condition that lowers your B vitamin levels.

There is minimal evidence that a supplement improves athletic performance. Some studies indicate that exercise may increase the amount of riboflavin and B6 that you need to consume. On the other hand, there is little risk in adding a B-complex supplement to your diet. Talk to your doctor first, of course.

Educate Yourself and Clients

Vitamins are essential micronutrients. We need to consume adequate amounts of B vitamins in our food or through supplements if necessary. This is why a varied diet of whole foods is so important. If you work with clients on their nutrition, share the facts about B vitamins and the vital role they play in health.

If you love learning about food, vitamins, and how to fuel for a healthy life, consider becoming a health or nutrition coach. The ISSA offers an online Nutritionist program to get you started.


"Office Of Dietary Supplements - Vitamin B12". 2021. Ods.Od.Nih.Gov.

"Vitamin B-Complex". 2015. Wa.Kaiserpermanente.Org.

Kennedy, David. 2016. "B Vitamins And The Brain: Mechanisms, Dose And Efficacy—A Review". Nutrients 8 (2): 68. doi:10.3390/nu8020068.

Woolf, Kathleen, and Melinda M. Manore. 2006. "B-Vitamins And Exercise: Does Exercise Alter Requirements?". International Journal Of Sport Nutrition And Exercise Metabolism 16 (5): 453-484. doi:10.1123/ijsnem.16.5.453.

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