Scientists found evidence that there are several factors involved in energy metabolism. These factors are essential for proper energy metabolism in the cells. These elements were collectively called B complex vitamins (Wildman).

Each individual member of this complex was studied in detail. The members of this family of B complex vitamins are

  1. Vitamins B1 (Thiamin)
  2. Vitamin B2 (Riboflavin)
  3. Vitamin B3 (Niacin)
  4. Vitamin B5 (Pantothenic acid)
  5. Vitamin B6 (Pyridoxine)
  6. Vitamin B9 (Folate)
  7. Vitamin B12
  8. Biotin

All these are needed to metabolize the macronutrients carbohydrate, proteins, and fats. These are all water-soluble vitamins. Though vitamin C and choline are also water soluble they are not included in the group of B complex vitamins because they do not directly participate in the chemical reaction pathways that metabolize or build energy nutrients (Wildman).

Origin of B Complex vitamins

All the B vitamins which come under this umbrella of B complex vitamins are synthesized by plants in their cells except B12 which is synthesized by bacteria. That is the reason why B12 is found only in animal products because bacteria in the guts of these animals make B12 vitamin (kennedy).

Functions of B complex vitamins

B complex vitamins are involved in several functions in the body. But majorly the functions can be clubbed into two major groups (Kennedy).

  1. Catabolic metabolism
  2. Anabolic metabolism

Catabolic energy production

According to  Encyclopaedia Britannica, Catabolism, the sequences of enzyme-catalyzed reactions by which relatively large molecules in living cells are broken down, or degraded. Part of the chemical energy released during catabolic processes is conserved in the form of energy-rich compounds (e.g., adenosine triphosphate or ATP).

In the energy generating catabolic reactions, one or more B vitamins are involved in every reaction. Deficiency of even one of the B vitamins will have an adverse effect on energy production in the body (Kennedy).

The most important B vitamins which play the role of co-enzymes in energy production are

  1. Thiamine
  2. Riboflavin
  3. Niacin
  4. Pantothenic acid.

Anabolic processes

According to  Encyclopaedia Britannica, Anabolism, also called biosynthesis, the sequences of enzyme-catalyzed reactions by which relatively complex molecules are formed in living cells from nutrients with relatively simple structures. Among the several essential compounds that are synthesized are amino acids, fatty acids, and pyrimidines. This process requires energy in the form of energy-rich compounds such as ATP  that are produced during catabolism (Kennedy).

B complex vitamins are needed as co-enzymes for anabolic processes. They play an intrinsic role in the complex processes involved in catabolic and anabolic reactions.

Dietary sources of B-complex vitamins

We have seen how important B-complex vitamins are for energy producing processes in our body. Therefore, we need to ensure we eat adequate amounts of B-complex vitamins providing foods. Here are some of the sources of B-complex vitamins

  1. Cereals (Brown rice)
  2. Cereal products (pasta)
  3. Whole grains
  4. Legumes
  5. Meat
  6. Organ meat (Liver, kidney)
  7. Eggs
  8. Milk and milk products
  9. Green leafy vegetables
  10. Green vegetables

Have you ever noticed that when we go to a doctor and the diagnosis is B-vitamin deficiency, the doctor gives us a supplement which gives us B-complex vitamins? They do not give us anyone B vitamin. That is because all the B vitamins are closely related and it is better to take all of them than any one individual at least till we get over the deficiency.