Health Benefits of B Complex

The B complex consists of eight water-soluble vitamins that perform essential and closely related roles in the body’s cellular function. The only other water-soluble vitamin is vitamin C; all others are fat-soluble. 

The vitamins that make up B complex are thiamine (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3), pantothenic acid (vitamin B5), pyridoxine (vitamin B6), biotin, folic acid, and the cobalamins (vitamin B12).

Most of the B vitamins are found in a wide range of foods because they are so important to cellular function. Some, like vitamin B12, are found mostly in meat and other animal food sources.

Health Benefits

The B vitamins help enzymes in our bodies do their jobs and are important for a wide range of cellular functions, like breaking down carbohydrates and transporting nutrients throughout the body. 

In addition, B complex can provide health benefits like:

Healthy Brain Function

The B vitamins play an inter-related role in keeping our brains running properly. Adequate amounts of B vitamins in the body are essential for optimal physiological and neurological functioning.

Some data shows that vitamin B6 in particular may play a role in the prevention of the neurological disorder Parkinson’s D isease.

Cancer Prevention

B vitamins may play a role in preventing the onset of various types of cancer. Some research shows that having the right amount of B vitamins in your body may help it resist the development of cancerous growth. 

Vitamin B has been associated with a lower risk of the skin cancer melanoma in particular.

Stress and Chronic Fatigue

If you are looking for ways to combat stress, vitamin B complex supplementation may help. Research shows that the B vitamins can significantly benefit mood and reduce the physiological response to stress.

For people with Chronic Fatigue Syndrome (CFS), vitamin B complex may help to reduce the severity of symptoms as part of a nutritional approach to treatment.

Health Risks

Although B complex offers many health benefits and is essential to the body’s overall function, supplementing with B vitamins does carry some risk, especially at high dosages. 

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Because B vitamins are water-soluble, it’s difficult to overdose on them because your body will flush out the excess. However, it is possible to experience negative effects from too much of the vitamins. 

Lung Cancer

Although B complex has been shown to help prevent many cancers, there is evidence to show that it may increase the likelihood of developing lung cancer in men who smoke. Researchers believe the B vitamins may help small and previously undetected tumors grow faster.

Peripheral Neuropathy

B complex contains vitamin B6, and an overdose of this vitamin (200 mg or more per day) can lead to a loss of feeling in the arms and legs. This is usually temporary and will go away once you stop taking the vitamin, but in some cases the effect can be permanent.

Liver Damage

B complex also contains niacin (vitamin B3). In high doses, niacin can cause skin flushing. If you take high doses over a long period of time, niacin can cause damage to the liver.

Amounts and Dosage

The recommended daily allowance (RDA) of B complex vitamins varies by age, gender, and condition. Check supplement formulations with your doctor to make sure the dosages in them are appropriate for you. 

You can also find B complex vitamins in a variety of food sources, including cereal grains, meat, poultry, eggs, fish, milk, legumes, and fresh vegetables.

WebMD Medical Reference Reviewed by Dan Brennan, MD on September 19, 2020

Sources

Sources:

Advances in Clinical and Experimental Medicine: “B-Group Vitamins: Chemoprevention?”

Biomedicine & Pharmacotherapy: “Chronic Fatigue Syndrome (Cfs): Suggestions for A Nutritional Treatment in the Therapeutic Approach.”

Colorado State University: “Water-Soluble Vitamins: B-Complex and Vitamin C.”

Harvard Medical School: “B Vitamins May Raise Risk of Lung Cancer in Men Who Smoke.”

Harvard School of Public Health: “B Vitamins.”

Medicine: “Effect of Vitamin B Supplementation on Cancer Incidence, Death Due to Cancer, and Total Mortality: A Prisma-compliant Cumulative Meta-analysis of Randomized Controlled Trials.”

NHS: “B Vitamins and Folic Acid.”

Nutrients: “Associations between B Vitamins and Parkinson's Disease.”

Nutrients: “B Vitamins and the Brain: Mechanisms, Dose and Efficacy.”

Nutrients: “A Systematic Review and Meta-Analysis of B Vitamin Supplementation on Depressive Symptoms, Anxiety, and Stress: Effects on Healthy and 'At-Risk' Individuals.”

USDA: “Vitamins and Minerals.”

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