Presentation Overview Comparison of vitamins in the body. Diagnosing deficiency and toxicity. The fat soluble vitamins, A, D, E, K. Notable health implications. Chemical Forms. Intake Need. Functions. Deficiency. Toxicity. Food Sources.
Water Soluble: absorbed into blood stream directly, circulate, travel, and stored in water compartments, excrete in urine, without intake deficiency signs and symptoms occur more quickly, toxicity is possible though shorter lived when intake is normalized. Fat Soluble: absorbed into lymph, many require protein carriers, associate with fat, not readily excreted, without intake deficiency signs and symptoms occur more slowly, toxicity is possible and longer lived even when intake is normalized. Comparison of Vitamins in the Body
1.Dietary records: Demonstrate low/high intake and/or confirm a metabolic or physiological problem that creates an altered need. 2.Clinical deficiency or toxicity symptoms: A re compatible with low/high dietary intake or altered need. 3.Biochemical tests: Such as blood levels, tissue levels & urine levels demonstrate low/high body levels of the nutrient. 4.Nutrient supplementation: Serves as biological evidence by correcting the deficiency signs & symptoms. For toxicity, removal of the excess. Diagnosing Nutritional Deficiency or Toxicity
The Fat Soluble Vitamins
Vitamin A Chemistry A family of compounds including: –Retinol, Retinal, Retinoic acid –Pro-Vitamin A carotenoids like beta-carotene Retinyl Esters (animal foods) Beta-Carotene (plant foods) Retinal (vision) Retinol (reproduction) Retinoic Acid (Growth Regulator)
Vitamin A Functions Vision Internal & external surface linings (epithelial cells) Growth Reproduction Embryonic development Gene expression Immune function Provitamin A forms have antioxidant properties
Vitamin A Deficiency vs Toxicity Deficiency (<66% of DRI) Approx. <500 µg RE/day Adequacy DRI: µg RE/day RDI: 5,000 IU Toxicity (>UL) >3,000 µg RE/day Hypovitaminosis A Bone & tooth: Impaired growth Central Nervous System: Night blindness, complete blindness (Xerophthalmia) GI System: Diarrhea Immunity: Depressed immunity, more infections Skin: Hyperkeratosis (thickened skin) Normal vision, gene expression, reproduction, embryonic development, epithelial cell maintenance, growth, and immune function Bone & tooth: Decreased bone mineral density Central Nervous System: Headache, vertigo GI System: Nausea and vomiting, liver abnormalities Neuro-Muscular: Incoordination Skin: orange color with excess beta-carotene Other: Retinoid embryopathy Adult deficient, adequate, toxic values 25 mg beta- carotene (pro- vitamin A is safe to take daily if you are not a smoker or drinker).
Vitamin A: Food Sources Retinol: (animal) Fortified milk, cheese, butter, margarine Eggs Liver Beta-Carotene: (Plant) dark green leafy vegetables broccoli, deep orange fruits, & vegetables
Vitamin A in Foods Adult DRI: µg RE/day
Vitamin D Chemistry Synthesis & Functions REGULATES Ca-P Balance Increases bone mineralization Increases intestinal absorption of calcium Increase phosphorus excretion Antiproliferative Prodifferentiation
Vitamin D Deficiency vs Toxicity Deficiency (<66% of DRI) Approx. <3 µg/day Adequacy DRI: 15 µg/day RDI: 400 IU = 6.5 µg Toxicity (>UL) >50 µg/day Rickets (children) Osteomalacia (adults) Bone & tooth: poor growth, bowed legs, soft bones, pigeon chest, knocked knees, and malformed teeth in children. Porous bones in adults. Cardio-Vascular: increased circulating levels (PTH) and (AlkP) and decreased circulating levels of serum phosphorus GI System: Decreased calcium absorption Normal calcium and phosphorus balance and cell metabolism Hypervitaminosis D characterized by high levels of 25(OH)D from supplementation Cardio-Vascular: High blood calcium Central Nervous System: Weakness GI System: Nausea, vomiting, anorexia Other: Kidney stones, increased thirst, urination, and urinary calcium Adult deficient, adequate, toxic values Needs are based upon an inadequate exposure to sunlight. Sunlight not implicated in toxicity.
Vitamin D: Sources Fortified products like milk, margarine, & some cereals Eggs & fatty fish Self-synthesis with unprotected peak sunlight exposure
Vitamin D in Foods Adult DRI: 15 µg/day
Vitamin E Chemistry A family of alpha, beta, gamma, delta tocopherols & tocotrienols. Alpha-tocopherol is believed to be the most active form.
Vitamin E Functions And at the molecular level And at the molecular level
Vitamin E Deficiency vs Toxicity Deficiency (<66% of DRI) Approx. <10 mg/day Adequacy DRI: 15 mg/day RDI: 30 IU Toxicity (>UL) >1,000 mg/day Premature infants: hemolytic anemia Adults: not well characterized Normal cell membrane integrity, reduced oxidative stress, and molecular functioning Relatively nontoxic Toxicity with supplements Interferes with vitamin K’s role in blood clotting, augmentation of anti-blood clotting medication and increases hemolysis Adult deficient, adequate, toxic values
Vitamin K Chemistry Phylloquinone (K1) from plant sources & naphthaquinones (K2, multiple forms) from animal sources & gut bacteria.
Vitamin K Deficiency vs Toxicity Deficiency (<66% of DRI) Approx. <60 µg/day Adequacy DRI: µg /day RDI: 90 µg Toxicity (>UL) Not Determined Cardio-Vascular: Increases clotting time, hemorrhaging with cut or injury Normal blood clotting & bone metabolism Poorly described in adults GI System: High levels from supplemented menadione causes jaundice and liver damage in infants Cardio-Vascular: Interference with anti- blood clotting medication Adult deficient, adequate, toxic values
Vitamin K: Sources Green leafy & cruciferous vegetables Soybeans Some plant oils Vitamin K is made by bacteria in the gastrointestinal tract
Vitamin K in Foods Adult DRI: µg/day
Summary Diagnosing & confirming a nutrient deficiency or toxicity requires a diet analysis, clinical evaluation, biochemical analysis, & evaluating the response to corrected intake levels. Toxicities and deficiencies take longer to develop for fat soluble vitamins as compared to water soluble vitamins. The fat soluble vitamins are grouped by their solubility in oil. The fat soluble vitamins have specific chemical forms & functions in the body. DRIs exist for essential fat soluble vitamins: A, D, E, & K. Deficiency & toxicity signs & symptoms are unique for each of these nutrients as are their food sources. References for this presentation are the same as those for this topic found in module 5 of the textbook