Nowadays, people frequently face fatigue, tiredness and low levels of energy. In the absence of underlying disease, these symptoms could be due to insufficient levels of vitamins and minerals, particularly vitamin B complex.  This blog will reflect the interrelationship between vitamin B and how they are related to energy metabolism.

Carbohydrates are the primary source of energy but their breakdown depends upon various enzymes, co factors and minerals for their role.

These water soluble vitamin B are important cofactors of enzymatic reactions and play a significant role in releasing energy.

What should be done to alleviate deficiency ?

Increase intake of dietary rich sources of vitamin B.

Vitamin B Types

Food Sources


Sunflower seeds , wheat germ , fortified grains


Organ meats, mushrooms, fortified grains


Chicken , lentils


Liver, fish , yoghurt ,avocado


Salmon, potatoes , chickpeas


Leafy greens, beans, fortified cereals and grains


Meats, eggs, seafood , dairy

 Specific food sources ,vitamin B12 and B6 are limited and present in traces only.

In order to make up for the insufficient levels of vitamin B, multivitamin tablets containing vitamin B complex should be taken under doctor’s guidance.

Energy Metabolism in the body

In cellular respiration, energy is transformed into ATP which happens in the mitochondria of the cell. Glucose is the preferred source of ATP , but if necessary other source of energy (carbohydrate, fat, protein) can be metabolised to acetyl coA , which then enters the citric acid cycle and be oxidised to Co2 and water.




Coenzymes , cofactors , active electron and proton carriers are involved in the ATP-generating respiratory chain. For instance , thiamine pyrophosphate (TPP; vitamin B1), CoA (containing pantothenic acid, Vitamin B5 ), (FMN;FAD  derived from vitamin B2) biotin (Vitamin B 7), CoA and FAD are involved in haem biosynthesis.

B complex vitamins - Necessary Coenzyme in energy metabolism

They act as substances that enhance or are necessary for the action of enzymes.

Types of vitamin B

Function in energy metabolism

Thiamine (B1)

Essential for the conversion of carbohydrates to energy.

Needed for normal muscle functioning , including the heart muscles.

Involved in oxidative carboxylation reactions

Riboflavin (B2)

Acts as a cofactor in the mitochondrial respiratory chain ad release of energy from foods

Component of the coenzyme FAD

Nicotinic Acid (B3)

It is a cofactor in the mitochondrial respiratory chain ad release of energy from foods

Transformation into NAD and NAPD , key role in oxidation.

Pantothenic Acid (B5)

It is a component of a coenzyme and plays a role in the Krebs cycle.

It is involved in metabolic reactions that help extract energy from fatty acids.

Pyridoxine (B6)

Helps in the release of energy from foods

It is a cofactor for nearly 100 enzymatic reactions, mainly protein and amino acid metabolism.

Biotin (B7)

As a cofator, involved in the metabolism of:-

  • Carbohydrates to glucose
  • Fats to fatty acids
  • Protein to amino acids and
  • Amino acids to glucose (gluconeogenesis)
  • Utilisation of B vitamins

Folic Acid (B9)

Around 30-50% of cellular folates are located in the mitochondria.

It is essential for metabolic pathways involving cell growth , replication.

Vitamin (B12)

Essential for metabolism of fats and carbohydrates

In conclusion, as discussed above, each type of vitamin B plays an important function in the metabolism of carbohydrates, fats, and protein.

Energy yielding nutrients should be a part of everyone’s diet and meeting the requirement through dietary sources and supplements will help carry out the physiological function.


  • Laquale, Kathleen M. (2006). B-complex vitamins' role in energy release. In Movement Arts, Health Promotion and Leisure Studies Faculty Publications. Paper 25.Available at:
  • HUSKISSON1, 2007.The Role of Vitamins and Minerals in Energy Metabolism and Well-Being.The Journal of International Medical Research

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