Vitamins Flashcards
Are vitamins essential?
Indispensable in human diets-Can’t be synthesized in sufficient quantity to meet individual needs; Vital dietary component; Vitamins with diverse biochemical functions;
How many vitamins are universally recognized at present?
13
History
Certain foods cured “illnesses”
Ancient Egyptians treated night blindness with juice from liver
Diseases like Scurvy, Beriberi, Pellagra and Pernicious Anemia prevented
Vitamins Definition
Organic, essential nutrients required in small, limited amounts to perform specific functions that promote growth, reproduction or maintenance of health and life
Vitamine
Vital (Life)
Amine (Contain Nitrogen)
Examples of Water-Soluble Vitamins
B-Vitamins and Vitamin C
Absorption of Water-Soluble Vitamins
Directly into blood
Transport of Water-Soluble Vitamins
Travel freely
Storage of Water-Soluble Vitamins
Freely circulate in water-filled parts of the body
Excretion of Water-Soluble Vitamins
Kidneys detect and remove excess in urine
Toxicity of Water-Soluble Vitamins
Possible when consumed from supplements
Requirements of Water-Soluble Vitamins
Frequent doses (1-3days)
Examples of Fat-Soluble Vitamins
Vitamins A, D, E and K
Absorption of Fat-Soluble Vitamins
First into lymph, then blood
Transport of Fat-Soluble Vitamins
Many require protein carriers
Storage of Fat-Soluble Vitamins
Trapped in cells associated with fat
Excretion of Fat-Soluble Vitamins
Less readily excreted, the to remain in fat-storage sites
Toxicity of Fat-Soluble Vitamins
Likely to reach toxic levels, when consumed from supplements
Requirements of Fat-Soluble Vitamins
Needed in periodic doses (Weeks or months)
Coenzymes
Organic, dialyzable, thermostable molecule that functions with enzyme to facilitate biochemical reaction (B-Vitamins)
Thiamin
First vitamin discovered (1926-1936); Thiamin pyrophosphate (TPP) is coenzyme vital to tissue respiration (co-carboxylase)
Thiamin Triphosphate (TTP)
Regulates nerve impulse transmission, concentrated in neuronal cells and other excitable tissues like skeletal muscle (Non-coenzyme)
Beriberi
“I can not, I can not.” in Sinhalese
Thiamin deficient individuals are weak due to impaired function of cardiovascular, muscular, nervous, and gastrointestinal systems
Symptoms: appetite loss, weight loss (marasmic), fatigue, vomiting, diarrhea, edema, dyspnea, cyanosis, cardiac failure/death
Dry: Peripheral neuropathy and extreme wasting
Wet: Peripheral neuropathy and congestive heart failure
Infantile Beriberi
Breast-fed infant from mother with beriberi-thiamin deficiency; mainly “Wet”-heart failure and marked peripheral edema; fatal-acute onset, formerly common in East Asian countries where rice is consumed, reversible with Thiamin (B1), occurs 2-6months
RDA/DRI for Adult Males/Females of Thiamin
Males: 1.2mg/day
Females: 1.1/mg/day
Food sources of Thiamin
Pork, Whole-grain products, Legumes
Thiamin Clinical Applications
Maple syrup urine disease (MSUD), Thiamin responsive megaloblastic anemia, Thiamin responsive lactic acidosis
Riboflavin Role
Precursor of essential coenzymes, Flavin mononucleotide (FMN), Flavin adenine dinucleotide (FAD), Coenzymes participate in oxidation-reduction reactions, Participation in drug metabolism, Lipid metabolism and Powerful antioxidant
Ariboflavinosis
Deficiency; Early symptoms- Weakness, Fatigue, Mouth pain and tenderness, Photophobia, Personality change; Advanced symptoms- Cheilosis, Angular Stomatitis, Glossitis, Dermatitis, Corneal vascularization, Anemia, Brain dysfunction; Conditions that increase risk- Congenital heart disease, Certain cancers, Alcoholism, Diabetes mellitus, trauma and stress, Thyroid disease, Oral contraceptives
DRI for Adult Males/Females of Riboflavin
Males: 1.3mg/day
Females: 1.1/mg/day
Food Sources of Riboflavin
Milk and other dairy products, Whole grain/enriched bread and cereal products, Dark green leafy vegetables
Niacin Role
Precursor of coenzymes- Nicotinamide adenine dinucleotide (NAD), Nicotinamide adenine dinucleotide phosphate (NADP), Several enzymes (dehydrogenases) require NAD and NADP; Coenzymes participate in oxidation-reduction reactions (essential for energy production)
Pellagra
Deficiency disease
Pelle = Skin
Agra = Rough
The four D’s of Pellagra
Dermatitis, Dementia, Diarrhea, Death
Pellagra Symptoms
Sensitivity to sunlight, Aggressive behavior, Dermatitis, Alopecia, Glossitis, Insomnia, Mental Confusion, Ataxia, Paralysis of extremities, Diarrhea, Dementia, Dilated Cardiomyopathy (heart becomes weak and enlarged)
DRI for Adult Males/Females of Niacin
Males: 16 NE/day
Females: 14 NE/day
1 NE = 60mg tryptophan = 1mg niacin
Food Sources of Niacin
Protein rich food (Meat, fish, poultry and peanut butter), Enriched breads and cereal, Whole grains
Clinical Applications of Niacin
Treatment of hypercholesterolemia, mental disorders, arthritis, dermatological conditions