Breaking Down the B Vitamins

By Malisa M. Carullo, BSc, MSc, ND

B vitamins are water-soluble vitamins that are commonly purchased by consumers looking to “obtain more energy.” They are sold in combination as a B complex as well as single-ingredient formulas, but how do you know which is best for you? Since each B vitamin has a list of specific roles it plays in the body, it is important to ensure adequate amounts are being consumed. Let’s look at each of these vitamins a tad closer.

B1: Thiamin

Vitamin B1 helps convert carbohydrates into energy. It is involved in more than 24 biochemical reactions in the body as a cofactor in energy production.1-2 Without enough B1, one may feel tired.1-2

A few food sources for B1: beans and sunflower seeds.1-2

B2: Riboflavin

Vitamin B2 is also involved in the production of energy. It is a cofactor in the synthesis of both adrenal and thyroid hormones, iron metabolism, and red blood cells.1-2 Riboflavin also plays a role in the immune system, as it is used in the production of antibodies.1-2

Vitamin B2 can be obtained from eating eggs, salmon, and almonds.1-2

B3: Niacin

Niacin plays a role in many metabolic functions of the body. It is involved in carbohydrate and fat metabolism, blood sugar regulation, and the production of sex hormones.1-2 Niacin is often not a problem to obtain in the Standard American Diet.1-2

Common sources are meat, fish, and enriched grains.1-2

B5: Pantothenic acid

Vitamin B5 is best known for its ability to improve fatigue and the body’s ability to cope with stress because it is involved in the synthesis of neurotransmitters, hormones, and cholesterol production.1-2

Foods such as avocados and eggs contain pantothenic acid.1-2

B6: Pyridoxine

Vitamin B6 is involved in many critical body systems such as the immune system, red blood cell production, and the production of neurotransmitters.1-2 Low vitamin B6 has been associated with impaired immune function and mental health issues related to mood.1-2

Adding green leafy vegetables, nuts, or beans to the diet will ensure adequate intake of pyridoxine.1-2

B7: Biotin

Biotin is well-known as the vitamin to consume to maintain healthy hair, skin, and nails.1-2 This is because biotin stimulates keratin production in hair and can increase the rate of follicle growth.1-2 In addition, biotin plays a role in carbohydrate and fat metabolism.1-2

Vitamin B7 can be obtained from egg yolks, salmon, and avocados.1-2

B9: Folate

Folate is very important, as it is critical for cell growth, cell division, and DNA synthesis.1-2 For these reasons, it is recommended for pregnant females to minimize birth defects in babies.1-2

Many foods contain folate such as spinach, meat, and fish.1-2

B12: Cobalamin

Vitamin B12 is necessary in several important body functions. It is vital for DNA production, production of red blood cells, and neurological health.1-2 This vitamin plays a key role in regulating the nervous system, cognitive function, and mood.1-2 B12 is needed to convert folate (vitamin B9) to its active form. A deficiency in this vitamin could cause symptoms of fatigue, weakness, and memory loss.1-2 Since the majority of B12 is obtained from animal products, it is often recommended that vegans routinely have blood levels tested.1-2

Vitamin B12 can be found in fish, meat, and eggs.1-2


Although one should be able to obtain adequate amounts of B vitamins from diet alone, some individuals may need increased amounts due to current health status or prescribed medication(s).1-3

The chart below from the National Institute of Health outlines the recommended daily intake for each B vitamin.3

Recommended Daily Intakes (RDIs) for B Vitamins

B1 (Thiamin)1.2 mg1.1 mg
B2 (Riboflavin)1.3 mg1.1 mg
B3 (Niacin)16 mg14 mg
B5 (Pantothenic acid)5 mg5 mg
B6 (Pyridoxine)1.3 mg1.3 mg
B7 (Biotin)30 mcg30 mcg
B9 (Folate)400 mcg400 mcg
B12 (Cobalamin)2.4 mcg2.4 mcg

As you can see, B vitamins are essential for the body to function optimally. If you are considering supplementation with any B vitamins, consult your healthcare provider, who can evaluate your levels and recommend those that would be best suited for you.1-2


  1. Gropper, Sareen., Smith, Jack. Advanced Nutrition and Human Metabolism. Cengage Learning; 2012.
  2. Linus Pauling Institute of Science and Medicine. Linus Pauling Institute of Science and Medicine. Palo, Alto, CA: The Institute, 1991.
  3. National Institute of Health., Office of Dietary Supplements., Dietary Reference Intakes (DRIs): Recommended Dietary Allowances and Adequate Intakes, Vitamins. Accessed June 6, 2022.
Malisa M. Carullo, BSc, MSc, ND
Malisa M. Carullo, BSc, MSc, ND completed her Doctorate in Naturopathic Medicine at National University of Health Sciences in Chicago, Illinois. She completed her MSc. in biology at the University of Ottawa with an emphasis on genetics and molecular evolution. Malisa puts much focus on biological medicine and its treatment of chronic conditions, as well as healthy age management. She blends naturopathic medicine with sports medicine. She is currently working as a Clinical Affairs Liaison at Metagenics.

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