B Vitamins
Thiamin B1
Riboflavin B2
Niacin B3, Nicotinic Acid, Niacinamide
Biotin
Pantothenic acid B5
Vitamin B6 Pyridoxine
Folate Folic Acid, Folacin
Vitamin B12 Cobalamin
Thiamin or B1
RDA
Men - 1.2 mg/day
Women - 1.1 mg/day
Functions
part of coenzyme TPP (thiamin pyrophosphate) promotes conversion of pyruvate to Acetyl CoA
Occupies a special site on the membrane of nerve cells
Muscles depend heavily on thiamin
Deficiencies: (rare in US)
Homeless and alcoholics
Wernicke-Korsakoff syndrome
Heavy alochol consumptionm
Beriberi
Food sources
Major diet contributors
White bread, crackers, pork, hot dogs, luncheon meats, ready to eat cereals, orange juice
Nutrient dense foods
Pork products, sunflower seeds, legumes, wheat germ, watermelon
Comments
easily destroyed by heat easily dissolved in water
Riboflavin or B2
RDA
men - 1.3 mg/day women - 1.1 mg/day
At risk: no milk or milk products
Function
coenzymes forms are FMN and FAD used in energy metabolism support normal vision and skin health
Facilitates the release of energy from nutrients in all body cells
Deficiencies:
Arbiboflavinosis
reddened lips, cracks at corners of mouth lactose intolerant are vulnerable
Nervous system and eyes
Skin
Food sources milk, cheese and yogurt
Grains
Liver
Nutritional yeast
Nutrient dense foods
Liver, mushrooms, spinach, green leafy vegetables, broccoli, asparagus, lowfat and nonfat milk, cottage cheese
Comments ultravioltet light and irradiation destroy riboflavin reason milk is sold in opaque plastic containers stable to heat
Niacin or B3
Known as nicotine acid
Body easily converts nicotinic acid to nicotinamide, which is the major form of niacin in blood
RDA
Recommended intakes are stated in niacin equivalents men - 16 NE/day women - 14 NE/day
UL :35 NE/day
Can be made from amino acid tryptophan
Need 60 milligrams of tryptophan for 1 milligram of niacin
Functions
forms part of coenzyme NAD and NADP release energy from organic fuels maintain healthy intestinal tract for healthy skin lowers cholesterol
Claims not proven benefit diabetes alleviates arthritis relieves migraines
Deficiencies: (rare in US)
Pellagra
Food sources: poultry, meat and fish grains. Cereals dairy products and eggs leafy green vegetables
Nutrient dense foods
Mushrooms, wheat bran, tuna, chicken, turkey, asparagus, peanuts
Toxicity:
large doses over long periods can cause liver damage large doses like 3000mg/day diabetes, gastritis. Gout
100mg or more nausea, headaches, cramps excess of 2 grams/day skin discoloration, dryness, decreased glucose
Divide dietary protein by 6
Eg. 90 gm protein = 15 mg of niacin
Thiamin, Riboflavin, Niacin
Biotin
AI (Adequate Intakes)
30 micrograms/day
Functions:
coenzyme that carries carbon dioxide important in the Kreb cycle
Deficiencies: (rare) a protein in raw egg whites called avidin binds biotin (overconsumption of raw eggs) hair loss, dry skin depression, fatigue
Food sources widespread….organ meats, egg yolks meats, cereals
Pantothenic Acid (B5)
AI
5 mg/day
Function:
involved in more than 100 steps in the synthesis of lipids, neurotransmitters, hgb part of coenzyme A
Deficiencies: (rare) fatigue, insomnia, vomiting, nausea
Food sources: widespread in foods meats, mushrooms, grains, vegetables
Comments
hard NOT to get enough in diet claims taking 300mg..3x/day lower cholesterol
50% are destroyed on cooking
B6
Three forms pyridoxal pyridoxine pyridoxamine RDA
1.3 mg/day
Functions:
all 3 forms are converted to coenzyme PLP and PMP used in amino acid and fatty acid metabolism convert tryptophan to niacin and serotonin protein and urea metabolism alcohol is broken down into acetylaldehyde…breaks down PLP..thus B6 is destroyed drug …INH..treats TB…binds to B6 causing it to be inactive
Deficiencies: estrogen stimulates the breakdown of