Nutrition11 minerals

80 4 0
  • Loading ...
1/80 trang

Thông tin tài liệu

Ngày đăng: 30/11/2016, 13:38

Major Minerals Chapter 11 Major Minerals • A major mineral is required in the diet and present in the body in large amounts compared with the trace minerals • Minerals are inorganic elemental atoms or ions • Minerals are not changed during digestion or when the body uses them Major Minerals • Minerals are not destroyed by heat, light, or alkalinity • Some minerals assist enzymes • Some minerals have structural roles Minerals In the Human Body Minerals in Foods • Foods from both plants and animals are sources of minerals • Animal tissues contain minerals in the proportions that animals need Minerals in Foods • The mineral content of plants can vary dramatically depending upon the minerals in the soil where the plant is found • The maturity of the vegetable, fruit, or grain can affect the mineral content Mineral Bioavailability • The GI tract absorbs a much smaller proportion of minerals than vitamins • Once absorbed, excess minerals are difficult for the body to flush out • The body adjusts mineral absorption in relation to needs Mineral Bioavailability • Some minerals compete for absorption sites Megadosing with one mineral can impede absorption of another • High-fiber diets reduce absorption of iron, calcium, zinc, and magnesium • Phytate (a component of whole grains) binds minerals and carries them out of the intestine unabsorbed • Oxalate (found in spinach and rhubarb) binds calcium, reducing its absorption Mineral Bioavailability Sodium • Sodium (Na) is an essential nutrient • Sodium is a component of sodium chloride (table salt) • Sodium in the diet is essential for normal body function, but we shouldn’t eat too much salt • Major extracellular cation Magnesium Functions • Participates in more than 300 types of enzymemediated functions • Assists in DNA synthesis • Assists in protein synthesis • Assists in energy production in the ETS and glycolysis • Participates in muscle contraction • Participates in blood clotting Magnesium Recommended Intake • RDA for adults 19 – 30 years 400 mgs / day for men and 310 mgs / day for women • Ages 31-70 420mg / day men 320 mg / day women Magnesium Food Sources • Dietary intake comes primarily from plants • Whole grains and vegetables such as spinach and potatoes are goods sources • Legumes, tofu, and some seafood • Sesame seeds, cashews, almonds • Processed grains lose up to 80 % of the magnesium and enrichment does not replace Magnesium Food Sources • “Hard” water can contain some magnesium • High-fiber diets often have a negative effect on mineral absorption • High calcium intake from supplements can interfere with magnesium absorption Hypomagnesemia Causes • • • • • Kidney disease Associated with alcoholism Diuretic drugs Prolonged diarrhea Chronically poor diets Mineral Deficiencies • Deficiency in any of the three major intracellular minerals (magnesium, potassium, and phosphorus) usually is associated with deficiencies of the other two Hypomagnesemia Clinical Signs and Symptoms • Healthy people whose diets are deficient in magnesium usually have no signs or symptoms for a few weeks because of the large supply of magnesium stored in the bone • Short term deficiency: – Loss of appetite, nausea, and weakness • Long-term deficiency: – Muscle cramps, irritability, and confusion Hypomagnesemia Clinical Signs and Symptoms • Extreme: – Death due to heart rhythm problems Hypermagnesemia • Causes – Uncommon in the absence of Kidney disease – Use of magnesium containing antacids or laxatives • Clinical Signs and Symptoms – Nausea – General weakness Hypermagnesemia • Physicians sometimes prescribe high doses during pregnancy to stop premature labor – Frequent monitoring is required to avoid toxicity that can lead to respiratory paralysis Sulfur • Sulfur is not used alone as a nutrient • Sulfur is present in certain organic compounds (vitamins biotin and thiamine and amino acids methionine and cysteine) • Disulfide bridges help proteins form their tertiary and quartenary structures • Adequate protein intake ensures enough sulfur Deficiency is unknown in humans Hypertension • Hypertension – high blood pressure • Major risk factor for heart disease, kidney disease, and stroke • Genetic predisposition and high sodium diets • Excess weight tends to raise blood pressure • Exercise and weight loss tend to lower BP Hypertension • Reducing alcohol tends to decrease BP • Diets rich in calcium, magnesium, and potassium reduce blood pressure Osteoporosis • Osteoporosis means “porous bone” • In osteoporosis, bone mass or density declines and bone quality deteriorates Osteoporosis • The bones become fragile and vulnerable to fractures • Normal development and mineralization of bones requires calcium, phosphorus, flouride, magnesium, vitamin D, vitamin A, vitamin K, and protein [...]... sodium (by the kidenys), prolonged vomiting, or diarrhea • Replacement of water without sodium Hyponatremia • Symptoms of hyponatremia resemble dehydration • Treatment involves replacement of fluids and minerals through liquids and foods or intravenous solutions if necessary Hyponatremia • Severe hyponatremia causes extracellular fluid to move into cells, causing them to swell • Brain cells swell – headache,
- Xem thêm -

Xem thêm: Nutrition11 minerals , Nutrition11 minerals , Nutrition11 minerals

Gợi ý tài liệu liên quan cho bạn

Nạp tiền Tải lên
Đăng ký
Đăng nhập