VITAMIN B3 .STRUCTURE ,FUNCTION ,TOXICITY

1. NICOTINAMIDE (VITAMIN B3 )
Submited to Dr Jasmine
Submitted by Abhishek Sharma

2. NAMES OF VITAMIN B3
• Niacin
• Niacinamide Or Nicotinamide
• Vitamin P Or Pp (Pellagra Preventive)
• Pellagra Preventive Factor
• Anti Black Tongue Factor
• Nicotinic Acid
• Vitamin G (After Goldberger’s Death)

3. CHEMICAL NATURE
• Nicotinamide is the amide derivative of nicotinic acid (pyridine
3 carboxylic acid) and is the form in which it functions in the
body
• Nicotinamide is a stable vitamin and is not easily destroyed bt
heat, acid, alkalis or oxidation

4. Sources
• Nicotinic acid can be synthesized from tryptophan in the body
tissues, since animals can convert acid to amide containing
coenzyme ,if diet is adequately supplied with proteins rich in
tryptophan (however efficiency low ,in chicks 45:1)
• Because of this it is generally considered that exogenous
sources is also necessary
• Although cats posses the enzyme for conversion
•Rich sources
• Liver
• Meats ,sea food
• Yeast
• Groundnut and sunflower meals
• Cereal grains
• Milk and eggs contain precursor tryptophan

5. Metabolism
• Nicotinamide functions in the animal body as the active group of two
important coenzymes ; nicotinamide adenine dinucleotide (NAD) and
NADP ,these are involved in mechanism of hydrogen transfer in living cells
and involved in oxidative phosphorylation system ,TCA cycle and
metabolism of many molecules including pyruvate ,acetate, glycerol,
fattyacids

6. Deficiency symptoms
Pigs
Poor growth
Anorexia
Enteritis
Vomiting and dermatitis
Fowl
Bone disorder
Feathering abnormalities
Inflammation of mouth and esophagus
Pellagra
commonly referred to as 3 Ds
Dermatitis =Inflammation of skin
Dementia = confused, disoriented
Diarrhea =irritation/inflammation
of mucous membranes

7. Deficiency of B3
• Rumen fermentation some experiments have shown increased microbial
growth and increased propionic acid production
• Cell metabolism (increased utilization of carbohydrate and reduced lipid
mobilization ), nicotinic acid may be a useful supplement to dairy cows
particularly in situations like subclinical ketosis

9. Assessment of B3 Status
• Urinary excretion of niacin metabolites
• N-methyl nicotinamide
• 2-pyridone

10. Toxicity of NIACIN
• Toxicity symptoms
1. Painful flush,
2. hives, and rash (“niacin flush”)
3. Excessive sweating
4. Blurred vision
5. Liver damage,
6. impaired glucose tolerance