Minerals S10(2) with class notes.doc

PAGE PAGE 2 Sarah H. Short, Ph.D.,Ed.D.,R.D. Minerals Minerals are classified as major if they are needed in the diet at levels of 100 mg/day or more. These minerals are Calcium Ca, Phosphorus P, Magnesium Mg, Sodium Na, Potassium K, Choride Cl. Trace minerals are needed in amounts no higher than a few mg/day. These include Fe, Zn, I, Se for which there are RDAs and Cu, Mn, F, Cr, and Mo for which there are ? estimated safe and adequate? daily dietary intake recommendation. There are other minerals needed for human nutrition, but there may not be enough known to set recommended allowances. Minerals are : essential (they cannot be made in the body), they do not provide energy, many are needed to make body structures such as bones, many are needed as activators for enzyme systems. poorly absorbed and can definitely be harmful if taken in excess. NO CALORIES Can get toxic amounts CALCIUM (Ca) Background (over 50% of females are low in calcium) 1. The body contains more calcium than any other mineral: 99% of it is in the bone with 1% in body fluids. 2. Calcium is one of the minerals necessary for bone formation (also need phosphorous (P), magnesium (Mg), vitamin D, and other) Bones are constantly gaining and losing minerals. During growth, children gain more bone than they lose. In later life, there is a gradual loss of bone. 3. The calcium that circulates in body fluids is absolutely necessary for life. The balance of calcium in the body involves a system of hormones and vitamin D . Levels of calcium in fluid are maintained at the expense of bone when there is inadequate calcium intake or absorption. If you are not getting enough calcium, the body just takes it out of the bones to use for all the needed functions. Of course, you are losing bone over the years. 99% of calcium is in the bone 1% in body fluids To make bone, need calcium, phosphorus, magnesium, vitamin D Will calcium help you loose wait? Probably not Calcium is absorbed every poorly Factors increasing Ca absorption Vitamin D Acid in stomach Lactose Growth hormone Functions of calcium Extra-skeletal (outside the bones) calcium (in body fluids) is needed for the normal response of nerves to stimuli muscle contraction blood clotting membrane permeability (control of passage of fluids through cell walls). normal rhythm of heart beat. Other advantages A high intake of Ca has been associated with lower blood pressure . May play a role in maintaining correct body weight Calcium absorption 1. Adults absorb about 25% of calcium they eat. Children and pregnant women absorb much more. Only 20 to 30% of ingested Ca is absorbed(sometimes only 10%). 2. The greater the need and the smaller the dietary supply, the more efficient the absorption, but it is still not good. 3. Factors that increase Ca absorption include: vitamin D , acid in stomach and in first part of small intestine, lactose, growth hormone. 4. Factors that decrease Ca absorption include: lack of stomach acid, insufficient amount of vitamin D; high phosphorus intake high fiber diet phytates acid in seeds, nuts, grain oxalates in rhubarb, spinach, beet greens form insoluble calcium oxalate salts (only 5% of calcium in spinach is absorbed); aging fat malabsorption; excess sweating (loss of calcium in sweat is 15 mg/day); prolonged bedrest or weightlessness. eating a low calcium diet drinking 2-3 cups of coffee results in greater bone loss, but drinking milk may offset the risks. A high urinary calcium excretion has been reported with a high-protein diet or protein supplements- perhaps only with low intakes of calcium Recommended Dietary Allowance 1. The RDA for males & females age 14-18 = 1300 mg/day; 19-50= is 1000 mg/day; age 51 - >70 = 1200 mg/day to help minimize bone loss. 2. Tolerable Upper Level =2500 mg 3. Surveys in the USA indicate that females do not have enough calcium. Deficiency 1. Rickets in children if they are also lacking vit D 2. Osteoporosis in adults causes easily broken bones. Genetics, sex hormones and physical activity along with vit D and other minerals influence bone mineralization. 3. For women, bone loss begins about age 30, proceeds slowly and continuously to menopause (approximately age 50). Bone loss increases at this time and continues at a high rate for the next 10 years. At that point taking more calcium only helps slightly. Providing women with supplemental estrogen seems to help. In men, bone loss is slow and steady from about age 30. 4. To REDUCE the risk of osteoporosis in later life, ensure the best calcium intake during bone formative years. It is important to meet the RDA at all ages, but intakes from childhood to age 25 should be stressed. Toxicity 1. High intakes (over 2.5 grams) may induce constipation, increase risk of urinary stones, and inhibit the absorption of iron, zinc and other minerals. 2. Very high intakes may cause harm to liver function. 3. Intakes much above the RDA are not recommended. Sources 1. Dairy products contribute more than 55% of the calcium intake of US population ( 1 cup of milk contains almost 300 mg of calcium). 2. Leafy green vegetables contribute some calcium ( broccoli, kale, collards), but calcium is poorly absorbed from these. 3. The soft bones of fish (in salmon and sardines) and rich sources. 4. Some calcium may be in water supplies. 5. Calcium from other sources (usually outside the USA) include fermented soybeans, small whole fish, mill powder used in grinding rice, lime used in making tortillas, ground rock used in Peruvian porridge. Supplements 1. There are many supplements on the market. Caltrate (Lederle) provides 600 mg per tablet; Oscal 250 elemental calcium; Tums, regular 200. Read the labels to discover the amount of Vitamin D per tablet. If many tablets per day must be taken, the vitamin D content may be too high. Antacids continued on a long term basis may lead to systemic alkalosis. Calcium (and magnesium and aluminum) antacid compounds are associated with acid rebound increased gastric secretion after initial acid neutralization. Calcium carbonate therapy causes occasional side effects of alkalosis, hypercalcemia, hypercalciuria and constipation. 2. To see if supplement will dissolve, drop a single calcium tablet into 6 oz. vinegar which mimics the acid environment of the stomach. Stir occasionally. After 30 min., the tablet should be broken and 75% dissolved. 3. Calcium carbonate is composed of 40% Ca and 60% CO3. Tums lists 500 mg of calcium carbonate, but that is only 200 mg of pure calcium. Bone meal is not recommended as a calcium supplement since it comes from the bones of old animals that have accumulated lead . Dolomite (a mineral combination of calcium carbonate and magnesium carbonate) is no more effective than less expensive calcium supplements. OSTEOPOROSIS What is osteoporosis? a weakening of bone and a serious health hazard Osteoporosis is a metabolic bone disease with decreased bone mass, normal mineralization, normal bone histology and pathological fractures. Osteoporosis tends to be more severe in the spine and pelvis than in other parts of the skeleton. Lower back pain is the most common symptom. Loss of height follows extensive collapse of vertebra. Osteoporosis is the most common of the metabolic bone diseases and accompanies old age in both men and women Spinal bones may become so weak that they collapse, leaving a hunched back (dowager's hump). This can decrease a woman's height 2 to 8 inches (average 6 inches). Who is at risk? White, postmenopausal women seem to be at highest risk. By age 65, one out of four of these women will have osteoporosis related fractures. About 12 percent of the people with hip fractures associated with osteoporosis (estimated to be 150,000) will die of related complications. Postmenopausal middle aged and elderly women, compared to men, have 8 times the risk of osteoporosis for the following reasons: Name 5 reasons: less bone because smaller or shorter Woman can get pregnant And breast feed (use Ca) drink less milk than boys (girls think it?s fattening) Woman live longer Osteoporosis can affect young people and men as well as older women. Probable causes proposed were high protein intake (high intake of protein results in bone loss), lack of calcium, smoking, excessive caffeine, alcohol and inactivity. Factors affecting calcium absorption and utilization PHOSPHORUS in excess in the diet may or may not negatively affect calcium absorption. The problem is that high carbonated beverages/soda takes the place of milk intake and carbonated beverages contain phosphoric acid, ________ VITAMIN A in excess (75,000 IU per day) may stimulate bone loss. Vitamin A in such huge amounts have been prescribed for acne. FIBER reduces the bioavailability of many minerals including calcium. The type of fiber and the results of recommended high fiber diets on osteoporosis is unknown. SPECIAL DIETS such as calorie restricted diets for weight loss may be low in calcium. Strict vegetarian diets (with no animal foods) may be low in several nutrients including calcium ,if milk products are omitted. Vegetarians (or others) who eat large amounts of spinach, chard, beet greens (high in oxalicates) may not have enough calcium. The oxalicates combines with calcium making it unavailable for absorption. MEDICATIONS can increase urinary calcium excretion and contribute to bone loss. Some of these medications are isoniazid (to treat TB), corticosteroids (anti inflammatory agents), heparin (anticoagulant), tetracycline (antibiotic), aluminum containing antacids such as Maalox, Mylanta, Amphogel, Gelusel; furosemide (diuretic); caffeine (in coffee, tea, some soft drinks); nicotine (in cigarettes). DISEASES may decrease intestinal calcium absorption. Examples are malabsorption syndromes, cirrhosis, renal failure, diabetes, hypoparathyroidism, alcoholism, nontropical sprue, celiac disease. ALCOHOLISM may decrease appetite, and the alcohol may displace calcium rich foods in the diet. Alcohol may reduce the intestinal absorption of calcium due to decreased vitamin D absorption, steatorrhea, or a direct effect on intestinal mucosal cells. Chronic alcohol intake may lead to liver damage which can alter the metabolism of vitamin D. This will decrease calcium absorption. PHYSICAL ACTIVITY (such as walking) slows the rate of bone loss. Decreased activity reduces the efficiency of calcium utilization and contributes to bone loss. Bedridden, paralyzed patients or astronauts lose 200 to300 mg of calcium per day. Strategies for Prevention and treatment a. women should have 1200 mg of CALCIUM (Ca) daily by means of dietary calcium or oral supplements. Calcium carbonate is the best supplement because 40% of the calcium in this preparation is elemental Ca (a 600 mg tablet contains 240 mg of elemental calcium. Conjugated ESTROGEN (0.625 mg or the equivalent) appears to be the minimum dosage capable of slowing bone mass loss, but there are problems with this (see health provider). EXERCISE such as walking or swimming is valuable and should be part of the program. Physical activity will add bone mass and the form of exercise is important. Calisthenics have little effect, effective exercise must be gravitational (must involve active weight bearing movement such as brisk walking or must require vigorous muscle pull on bone. prescription drugs if necessary Note: The FDA cited over 18 manufacturers of Coral Calcium (2004) for making false claims that the supplement is a cure-all. High amounts of lead and mercury in Okinawa coral. Directions are for too high a dose. The environmental consequences or taking coral from the reefs is a disaster. It takes thousands of years for coral to grow. No quality control for this supplement. PHOSPHORUS Phosphorus is an essential component of bone mineral, where it occurs in the Ca:P of 2:1 About 85% (700 g) of the phosphorus in the adult body is found in bone. Phosphorus is absorbed very well by the small intestine as free phosphate. Infants absorb up to 70% of phosphorus in cow's milk and close to 90% of that in human milk. Functions 1. It has more functions than any other mineral 2. forms part of bones and teeth; 3. needed for absorption of glucose and glycerol; 4. helps transport fatty acids in the body; 5. important in energy metabolism (ATP high energy bonds); 6. essential element of all body cells (DNA); 7. phosphate buffering system 8. important in acid-base balance; 9. muscles need phosphorus to contract; 10. part of some proteins such as casein. Dietary Sources and Usual Intakes 1. Phosphorus is present in nearly all foods especially milk and milk products and liver and other animal-food protein sources.. 2. The mean daily phosphorus intake is approx imately 1,500 mg/day for adult males and 1,000 mg/ day for adult females - may be 15-20% higher because of phosphorus supplied by food additives. 3. Major contributors of phosphorus are protein rich foods & cereal grains + additives 4. About half the phosphorus in the USA diet comes from milk, meat, poultry, and fish. Cereal products contribute about 12%. 5. Meat, poultry, &fish, exclusive of bone, contain 15 -20 times more phosphorus than calcium 6. Twice as much phosphorus as calcium in eggs, grains, nuts, dry beans, peas, lentils 7. Availability of phosphorus in grains, especially bran, is doubtful because of phytates in grain which will bind with phosphorus.. Deficiency 1. Because almost all foods contain phosphorus, dietary phosphorus deficiency does not usually occur. 2. Patients receiving antacids with aluminum hydroxide for long time may have problems because aluminum hydroxide binds phosphorus making it unavailable. Recommended Allowances 1. Dietary phosphorus is more abundant than calcium in most U.S. diets, but high or low intakes of phosphorus are not a prob lem. 2. The RDA for phosphorus is 1,250 mg for males and females 9 through 18; 700 mg for 19 to >70 . The phosphorus content of human milk, 14 mg/100 g, is adequate for the full term infant. Excessive Intakes and Toxicity. Phosphorus levels present in normal diets are not harmful, certainly not in the presence of adequate intakes of' calcium and vitamin D. Over 4000 mg (4 grams) /day can cause calcification of nonskeletal tissues especially kidneys---have boney tissue where not supposed to be. Sample Questions/objectives: Identify 6 major minerals Define ?major? as in major minerals. Name 4 functions of calcium How well absorbed is calcium? When is peak bone mass achieved? ( age 25 to 30 How much calcium is there in Tums? Name 3 food sources of calcium Identify 4 reasons women are more susceptible to osteoporosis than men. Name 3 functions of phosphorous Name 2 food sources of phosphorus How well absorbed is phosphorus? Woman need to have 1200mg of Ca Magnetism Also part of bone and muscle Enzyme activator Transmission of nerve impulses Deficiency is rare ( seen in malabsorption, malnutrition, and alcoholism In anything green, legumes, nuts, whole wheat bread Iron Needed for red blood cells, hemoglobin in blood, transport oxygen around your system Anemia may result from a lack of iron in the diet Only 5 to 10% of iron in food is absorbed Increase iron absorption by increased Vitamin C intake Also by eating meat Increase absorption decreased by Tea Coffee Egg yolks Leady greens Fiber cereals Food sources Best source = liver Raisins ( not a good source Anything Enriched ( Leafy green vegetables not the best, animal sources = better (vitamins) Iron deficiency anemia is the most common deficient disease in the world Symptoms of anemia Fatigue Tongue is sore Hard to swallow Spoon nails Woman = loose blood during period Almost impossible to get enough iron Need to supplement, eat more meat, or get iron skillet Iron is needed for myoglobin in muscle Athletes may need more iron because they may get hurt Pica ( eat non food items May be iron deficient Iron Toxicity most common Young chil