B Complex Vitamins: Energy Metabolism Flashcards
What are the 8 b complex vitamins?
Thiamin, Riboflavin, Niacin, Pantothenic Acid, Vitamin B6, Biotin, Folate, Cobalamin
What do B vitamins do?
helpers, act as coenzymes
have both coenzyme and non-coenzyme roles
What are the three types of b complex vitamins
energy releasing, hematopoietic and other
Function of Thiamin
Dietary thiamin is converted to the active form thiamin pyrophosphate Functions: -decarboxylase reactions -transmission of nerve impulses -forms pentoses for dnarna synthesis
RDA and sources of thiamin
RDA: 1.2 men, 1.1 women
pork is richest natural source, enriched grain
Toxicity and Deficiency of Thiamin
Wet beriberi: affects cv system
Dry beriberi: affects nervous system
Wernicke korsakoff syndrome
Riboflavin overview
- light sensitive vitamin
- flavin mononucleotide
- flavin adenine dinucleotide
functions: energy metabolism, covnersion of some other b vitamins to active forms
Riboflavin RDA, sources
men: 1.3, women 1.1
dietary sources: dairy, enriched cereals, spinach, mushrooms
Riboflavin toxicity and deficiency
no ul, excreted in urine
Ariboflavinosis is rare and usually in combo with other deficiency
sore throat, mouth swelling
Niacin
nicotinic acid, nicotinamide, can be made from tryptophan,
60 mg of tryptophan is 1 mg of niacine
functions of niacin
energy metabolism, synthesize fat and cholesterol
RDA and sources of niacin
men: 16, women: 14
enriched whole grain breads and cereals, protein rich foods
niacin deficiency and toxicity
UL is 35 mg day to prevent flushing
Pellagra: niacin deficiency disease
4 Ds
Pantothenic Acid
component of coenzyme A
found in virtually all foods
Pantothenic Acid RDA, toxicity, deficiency
5 mg day
no toxicities
most common deficiency when other deficiencies are present
B6 bby
functions with over 100 enzymes
most involved in protein metabolism
RDA and sources of B6
males: 1.3 to 1.7
females: 1.3-1.5
sources: legumes, meat, fish poultry, nuts, peanut butter
B6 deficiency and toxicity
UL is 100mg per day to prevent nerve damage
Deficiency symptoms include sore tongue, skin inflammation, depression, confusion
Biotin bby
functions as a covalently bound cofactor to enzymes and other molecules
can be made in large intestine, stored in small amounts in liver
5 enzymes require it
Biotin AI and toxicity/deficiency
30 ug/d
biotin
no toxicity reported
deficiency is rare but serious: dermatitis, hair loss, neurological abnormalities
