What Are B Vitamins?
They help the body convert food into energy (metabolism), create new blood cells, and maintain healthy skin cells, brain cells, and other body tissues. There are eight types of B vitamin, each with their own function: thiamin (vitamin B-1)
riboflavin (vitamin B-2)
niacin (vitamin B-3)
pantothenic acid (vitamin B-5)
vitamin B-6
biotin (vitamin B-7)
folate (vitamin B-9)
vitamin B-12 Together, they are called the vitamin B complex. B vitamins often occur together in the same foods.
Explore:
Spotlight on Three of the Bs: Folate, Vitamin B6, and Vitamin B12
One of the advances that changed the way we look at vitamins was the discovery that too little folate is linked to birth defects such as spina bifida and anencephaly. Learn more about folate and health
Another line of research about folate and two other B vitamins, vitamin B6 and vitamin B12, explores their roles in reducing some types of cancer and heart disease. Vitamin B6 Vitamin B6, or pyridoxine, is a water-soluble vitamin found naturally in many foods, as well as added to foods and supplements.
It can also be added to foods or supplements.
Abstract
The B-vitamins comprise a group of eight water soluble vitamins that perform essential, closely inter-related roles in cellular functioning, acting as co-enzymes in a vast array of catabolic and anabolic enzymatic reactions. Their collective effects are particularly prevalent to numerous aspects of brain function, including energy production, DNA/RNA synthesis/repair, genomic and non-genomic methylation, and the synthesis of numerous neurochemicals and signaling molecules.
Scant regard has been paid to the other B vitamins. Furthermore, evidence from human research clearly shows both that a significant proportion of the populations of developed countries suffer from deficiencies or insufficiencies in one or more of this group of vitamins, and that, in the absence of an optimal diet, administration of the entire B-vitamin group, rather than a small sub-set, at doses greatly in excess of the current governmental recommendations, would be a rational approach for preserving brain health.
Related Terms:
Physiologic characteristics
Vitamin B 12 is a generic term for cyanocobalamin and hydroxocobalamin, two stable forms of cobalamin.
Cobalamins are unique because they are the only cobalt-containing organic compounds known to occur in nature, and they represent the only known biologic example of a metal–carbon bond. The cobalamins are composed of a nearly planar macrocyclic corrin ring (similar to porphyrin) covalently linked to a trivalent cobalt atom by four coordination bonds in a manner similar to iron binding in heme. As a group, the cobalamins are essential cofactors in several human enzymatic processes that lead to proper DNA formation.
A deficiency in them results in a megaloblastic anemia, as the flawed DNA fragments are left in the maturing erythrocyte. The sole natural and commercial source of cobalamin is synthesis by microorganisms. The average daily diet contains 5 to 30 μg of vitamin B 12 , of which 20% to 30% is absorbed.
Daily intake of 1 to 3 μg does little more than compensate for daily loss, but normally more than 1000 times this amount (up to 4 mg) is stored in the liver. When first ingested, the cobalamin liberated from food interacts with R proteins in the stomach. These “bodyguard” proteins bind tightly to cobalamin and protect it from acidic degradation.
The cobalamin is next adsorbed onto intrinsic factor, an “escort” glycoprotein secreted by the stomach parietal cells that has specific cobalamin-binding properties. Receptors for this transcobalamin II–cobalamin complex are ubiquitous, but are especially rich in the liver.