Vitamin B6 are also known as pyridoxine is a water soluble vitamin exist in three forms pyridoxine (the alcoholic form), pyridoxine amine (the amino form) and pyridoxal (the aldehyde form). These forms are interchangeable and comparably active. The interchangeable form of these vitamins are pyridoxine 5 phosphate, pyridoxal 5 phosphate and pyridoxamine 5 phosphate.

DATS of Vitamin B6
DATS (DIGESTION, ABSORPTION, TRANSPORTATION AND STORAGE) OF VITAMIN-B6 pyridoxine

Sources:

All these vitamins are found in food. Pyridoxine the stablest form and its phosphorylated form are present mostly in plants in an conjugated form pyridoxine glycoside. Pyridoxal phosphate and pyridoxal amine phosphate are mainly found in animals.

Much of the vitamins originally present in food and can be lost through processing, heating, canning, sterilizing and fewer loses through storage.

The plant sources of this vitamin include vegetables, fruits, bananas, nuts, pork, tomato paste.

Animal sources are chicken breast, red meat etc.

Sea sources are sirloin, salmon etc.

RDA (recommended dietary allowances):

The recommended dietary allowances are different for the individuals of different age groups. RDA for males, females and children are:

Gender

RDA

Men

1.3 micro gram

Women

1.3 micro gram

Children

2.0 micro gram

 

Functions of vitamin B6 in Human body:

Vitamin B6 performs many important roles in human body these are:

  • it helps in the metabolism of red blood cells, proteins and amino acids.
  • It also helps in the conversion of tryptophan to niacin.
  • It supports to the healthy immune function.
  • It helps in the transportation of selenium.
  • It also assist in the metabolism of calcium and magnesium.

DATS (digestion, absorption, transportation and storage) of vitamin B6:

Digestion:

Prior to be absorbed the phosphorylated form of vitamin B6 must need to be dephosphorylated. Alkaline phosphatases a zinc dependent enzyme found at the intestinal brush boarders or other intestinal phosphatases are used to hydrolyze the phosphatase to yield pyridoxine (PN), pyridoxal (PL) and pyridoxamine (PM).

Absorption:

PL, PN and PM are primarily absorbed in the jejunum by passive diffusion. At physiological intakes it is absorbed in its free form directly.

Transportation:

Most of the PL, PN and PM is released unchangeable into the portal circulation and are taken up by the liver. In liver these vitamins are primarily converted to PLP. PLP is the main form of vitamin in blood. Other forms of this vitamin are PL, PN, PM and PMP in blood. In blood it is bound to albumin in hemoglobin.

Storage:

Liver is the main organ that takes up and metabolizes newly absorbed vitamins. About 5-10% of this vitamin are absorbed in the liver. Muscle represents the major storage site of this vitamin i-e about 75-80%. Once the vitamin move inside the phosphorylation prevents its diffusion out of the cell. Pyridoxine kinase is used in phosphorylation.

Metabolism Of Vitamin B6 In Liver:

Most of the B6 metabolism occurs in the liver. Unphosphorylated forms of the vitamers are phosphorylated by a kinase using ATP within the cytoplasm of the hepatocytes.

The storage form of this vitamin are PLP, PNP and PMP while its circulatory forms are PN, PM and PL. So prior to its storage phosphorylation occurs while for transportation DE phosphorylation occurs.

Deficiency:

Deficiency of vitamin B6 leads to microcytic anemia. As vitamin B6 also helps in the conversion of homocysteine. Its deficiency may leads to its improper conversion and hyper homocysteine occurs. Impairs niacin synthesis from tryptophan. It also alters calcium and magnesium metabolism. In addtition to this glottis, neuropathy and some other complications are also the cause of vtamin B6 deficiency.

Mechanism Of Action:

For co enzyme action with in a cell, biotin is attached to four carboxylases:

Pyruvate Carboxylases

The co enzyme form of B6, PLP is associated with a vast number of enzymes the majority of which are involved in amino acids metabolism.

Some non-coenzyme role of this vitamin effects the action of steroid hormone and gene expression. Dysfunction of Vitamin B6 appears to diminish the activity of steroid hormone which in turns diminish the interaction of nucleoprotein with the DNA.

It also helps in the conversion of glycogen to glucose by assisting with glycogen phosphorylases.

In process of decarboxylation, transamination, deamination and other synthetic reactions B6 acts as an enzyme and involves in the transfer of phosphate group to another.