NUTR 202 1nd Edition Lecture 16 Ch 8 ContinuedCalcium absorption in GI depends on the availability of: Vitamin D & Parathyroid Hormone (PTH). Absorption also higher when needs are higherBioavailability of calcium is decreased in the presence of certain substances in foods: Tannins, fiber, phytates and oxalates. Minerals w/ same charge (Fe) Bioavailability of Ca is increased in pregnant women.Ca is the most abundant mineral in the body.RDA: 19-50 years = 1000 mg/day; UL= 2500 mg/daySources: dairy products, dark green vegetables, fish with bones, foods processed and fortified with calcium.99% of calcium in the body is found in solid mineral deposits in the bones and teeth. Will be at risk if Ca in 1% is not enough.  Provides structure for bones Also found in teethThe remaining 1% is found in intracellular fluid, blood and extracellular fluid for: Release of hormones Nerve transmission Muscle contraction Normal BP regulation*Decreased blood calcium:• Ý CalcitoninThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.• Ý PTH• Stimulates intestinal absorption, kidney reabsorption & bone-resorption. Increased blood calcium. At risk is Ca in the bones. PTH  active vitamin D  be able to absorb more Ca in small intestine. Rel. from bone.Too much or too little: UL: 2,500 mg/dayToo much calcium: Hypercalcemia: (usually from supplements  too much in bldstream) May impaired kidney function Calcium deposits in body Risk of calcium stonesConstipation & may interfere with absorption of certain minerals: iron, zinc, magnesium, and phosphorus. Remember bioavailability  minerals with same charge will compete to be absorbed. Osteopenia is: Reduced bone density below normal levels.Osteoporosis: The bone disorder characterized by reduced bone mass, increased bone fragility and increased risk of factures.Osteoporosis is the most common bone disease. 10 million Americans have osteoporosis (55%).Osteoporosis lead to 1.5 million fractures annually, which account for $18 billion per year in medical costs. By 2025, experts predict that these costs will rise to $25.3 billion. More common in women, increases with age, AA have DENSER bones; if thin you are at risk, lack of exercise, or diet low in Ca, Vitamin D, and high in Phosphorous. Ex: a 65-year-old woman who is thin and drinks alcohol will be at a greater risk than an overweight male, AA female who jogs, 20-year-old male who plays football.Phosphorous- Second most abundant mineral in body (need less than Ca in bone) Most located in bones (85%); hard mineral in bones & teeth  Remainder in cells and fluids outside cells, including bloodFxn: E metabolism/ ATP is made of 3 PHOSPHATE groups, PHOSPHOlipids, acid/base balance, enzyme activity (inactive  active need P), and DNA/ RNA contain P!Daily needs: Adults: 700 mg/day Food sources: Meat, fish, poultry, dairy, food additives (i.e. sodas), abundant in diet. Can lead topoor bone density bc reduce amt of Ca in bld.Excess Phosphorus intake: Calcification deposit in tissues Associated with poor bone density UL set at 4,000 mg/day for adults 19-50Phosphorus deficiency rare: Muscle weakness, bone loss, loss of appetite.Trace Minerals: Iron, zinc, copper, manganese, selenium, iodine, fluoride, chromium and molybdenum. They are required in an amount less than 100 mg per day. Trace minerals have been difficult to study, as they are difficult to remove from the diet. Absorption may be affected by bioavailabilityFluorideFunctions: Protects against dental caries. Fluoridated drinking water has reduced dental caries in U.S. Associated with bone health.Daily needs: Men 3.8 mg/day; women 3.1 mg/daySources: Fluoridated drinking water (foods are not a good source). Tea, bones of marine fish, toothpasteToo much: Fluorosis: mottling/staining during infancy/childhood. UL adults = 10 mg/day, much lower for infants and childrenToo little: Too little increases risk of dental caries. Less than 1mg/L. Flakes  brown spots in teeth. (Deficiency = caries!) Iron- Public Health concern *Found in 2 forms: Heme & Non-heme ironFunctions:1. Part of hemoglobin in red blood cells: Transport O2 to tissues and picks up carbon dioxide waste from cells2. Myoglobin3. Helps enzymes that make neurotransmitters in brain; send messages to rest of body4. Immune functionHeme iron: Part of hemoglobin and myoglobin; animal sources and easily absorbed (25%)Non-heme: Not as easily absorbed (17%); plant foodsDaily needs: Men and women >50: 8 mg/day. Women 19-50: 18 mg/day. Body only absorbs 10-15% of iron consumed. Absorption increases if body stores are low. Remember heme iron is absorbed more. Bioavailability: animal (heme) higher Sources of non-heme iron:  Iron-enriched bread and grain products, legumes, apricots, potatoes To enhance absorption of non-heme iron: KNOW THESE RECOMM. Consume food with high Vitamin C - eat PB (iron) with OJ  Consume w/ meat, fish, poultry (heme products)  Cook foods in iron pans or skilletsIt is estimated that as much as 80% of the world’s population may be iron deficient and 30% suffer from iron deficiency anemia. Most common nutritional deficiency worldwide: Iron deficiency anemia. Microcytic anemia (B6  HB & MB). (females, poverty, pregnant women, and growing children are at risk of iron deficiency).Too much iron from supplements: Constipation, nausea, vomiting, diarrhea Iron overload can damage heart, kidneys, liver, nervous systemHemochromatosis: A genetic disorder, can cause iron overload Leading cause of accidental poisoning deaths in children under 6 yearsCopper Aids in iron absorption in small intestine [ so helps reduce risk of iron deficient anemia ]  Cofactor for antioxidant enzyme, CuZn-Superoxide Dismutase (SOD) – so a Pro-Antioxidant FYI Good Sources: Organ meats, Seafood, Chocolate, Nuts, Seeds, Whole-GrainsZincMost abundant intracellular trace elementGene expression (DNA synthesis)Growth and Development (**children)Cofactor for 300+ enzymes, e.g., CuZn-SODPro- Antioxidant for protecting cells from free-radical damageToxic in excess; can decrease Cu bioavailabilitySelenium (Se)May help to fight cancer; another Pro-antioxidant= Cofactor for antioxidant enzyme Glutathione Peroxidase.Iodine FUNCTIONS: Used by thyroid to make thyroid hormones  regulate metabolic rate and