Nutrition Chapter 8 Minerals

Absorption

1.Food from Minerals from animal sources are usually more readily absorbed than those from plant sources. 2. Body need-more is absorbed if the body is deficient than if they body has sufficient quantities. 3. Tissue health-If the absorbing intestinal surface is affected by disease, its absorptive capacity is greatly diminished.

Hypercalcemia

Associated with the calcification of soft tissue.

Food Sources

Calcium in low oxalate greens such as bok choy, collard greens, kale, and turnip greens is absorbed and can be important source of calcium for vegetarians. Oxalic acid is a compound that is found in plants such as spinach, rhubarb, swiss chard, beet greens, and certain other vegetables and nuts that forms an insoluble salt with calcium thus interfering with the intestinal absorption of calcium. The bioavailability of calcium from supplements depends on the dose and whether it is taken with a meal. Calcium is best absorbed in doses of 500mg or less and when taken with food rather than on an empty stomach.

Muscle and nerve action

Calcium ions are required for muscle contraction and the release of neurotransmitters from neuron synapses.

Blood Clotting

Calcium is essential for the formation of fibrin which is the protein matrix of a blood clot.

Metabolic Reactions.

Calcium is necessary for many general metabolic functions in the body. Such functions include the intestinal absorption of vitamin b12, the activation of the fat splitting enzyme pancreatic lipase, and the secretion of insulin by the B cells of the pancreas.

Copper

Called the "iron twin" because both copper and iron are metabolized in the same way. Energy production and hemoglobin synthesis. Copper deficiency is rare. The UL for copper is 10mg/day Found in meats, soy, legumes.

Sulfur

Component of thiamin and biotin. Beauty mineral.

Absorption#2

Compounds found in foods may also affect the absorptive efficiency. For example the presence of fiber phytate or oxalate all of which are found in a variety of whole grains fruits and vegetables can bind certain materials in the GI tract thereby inhibiting or limiting their absorption.

Keshan Diease

Disease of the heart muscle that primarily affects young children and women of childbearing age and that can lead to heart failure as a result of cardiomyopathy. Selenium deficiency.

Iodine

Easiest and least expensive of all nutrient disorders to avert how they remain the number one cause of preventable brain damage. Cretinism is a congenital disorder resulting from insufficient thyroid hormone to the fetus during gestation. Characterized by physical deformity, dwarfism, mental retardation, and auditory disorders. Even mild iodine deficiency during pregnancy have a significant reduction in their intelligence. The amount of iodine in natural food sources varies considerably depending on the iodine content of the soil in which food was grown. Seafood consistently provides a good amount of iodine.

Calcium

Found in plant forms is sometimes bound to oxalate or phytate and thus not readily available. Calcium Vit D and estrogen needed for strong bones.

Magnesium

Has widespread metabolic functions, and it is found in all body cells. Major food sources of magnesium include nuts, soybeans, legumes, whole grains, oats and cocoa.

Fluoride

Main function in human nutrition is to prevent the development of dental caries. Fluoridation of the public water supply is responsible for an added decline in dental caries. Crab, shrimp, raisins, grape juice, hot breakfast cereals and tea contain fluoride.

Major Minerals

Major minerals have a recommended intake of more than 100mg/day. The seven major minerals are calcium,phosphorus,sodium,potassium,magnesium,chloride, and sulfur.

Transport

Minerals enter the portal blood circulation and travel throughout the body bound to plasma proteins or mineral specific transport proteins.

Classes of Minerals

Minerals occur in varying amounts in the body. For example a relatively large amount of our total body weight is calcium. An adult who weighs 150lbs has approximately 2.25lb of calcium in the body. Iron on the other hand is found in smaller quantities

Bone and Tooth Formation

More than 99% of the body's calcium is found in the bones and teeth. Approximately 1.5% of adult body weight is calcium. If dietary calcium is insufficient during critical periods then construction of healthy bones is hindered. (The initial formation of the fetal skeleton, childhood growth or the rapid growth of long bones during adolescence)

Phosphorus

Most commonly found in combination with four oxygen atoms. The calcification of bones and teeth depends on the deposition of hydroxyapatite. Phosphorus in the form of phosphate is necessary for the controlled oxidation of carbohydrate, fat, and protein to release to energy in their covalent bonds. Phosphate is an important chemical buffer that helps to maintain the pH homeostasis of body fluids. The typical American diet contains enough phosphorus to meet body needs. A person must be completely deprived of food for an extended period to develop a dietary phosphorus deficiency. A person who persistently consumes large amounts of antacids that contained aluminum hydroxide. Phosphorus is part of all living tissue and is found in all animal and plant cells.

Hypothyroidsm

Occurs when a poorly functioning thyroid gland does not make enough T4 thereby greatly reducing the basal metabolic rate.

Osteoporosis

Osteoporosis abnormal thinning of the bones. Increase in life expectancy osteoporotic bone fractures are progressively more common among elderly men as well. Causes not enough calcium, lack of physical activity, side effects of medication.

Sodium

Plentiful in the body. 2300 daily intake. Chloride comes from salt. The main function is the maintenance of body water balance. Sodium occurs naturally in foods.

Potassium

Potassium is the major intracellular electrolyte. Potassium ions also play a role in nerve impulse transmission to stimulate muscle action. Along with magnesium and sodium, potassium acts as a muscle relaxant. Potassium is necessary for the release of insulin from pancreatic cells. Found in fruit and diuretics. Potassium intake is equal to the sodium intake may help to prevent the development of hypertension. Hypokalemia is more likely to develop during clinical situations such as prolonged vomiting or diarrhea, severe malnutrition or surgery. Potassium is an essential part of all living cells thus it is abundant in natural foods.

Chloride

Predominately found in the extracellular fluid compartments where it helps to maintain the water and acid base balances. Chloride is An element of the hydrochloric acid that is secreted in the gastric juices. The only known dietary cause of chloride toxicity is as a result of severe dehydration. Dietary chloride is almost entirely provided by sodium chloride.

Selenium

Present in all body tissue except adipose tissue. Essential part of antioxidant enzyme glutathione. Deficiency causes cancer. Best source is brazil nuts. The most common symptoms of selenium toxicity are hair loss, joint pain, nail discoloration, and GI upset. Highly available for intestinal absorption. Amount of selenium in food depends on the quantity in soil that is used to graze animals and grow food. Pork, turkey, lamb, liver.

Adolescence

Rapid bone growth requires increased calcium, phosphorus, and magnesium. Depending on adequacy of their diet supplements that combine iron with folate may be indicated for girls as they being menstruating.

Wilson's disease

Rare autosomal recessive genetic disorder that causes abnormally high storage of copper in the body.

Zinc

Required for optimal function of more than 300 enzymes. All aspects of the immune system are dependent on adequate zinc availability. Adequate intake is imperative for good health during periods of tissue growth such as childhood and adolescence. Deficiency commonly causes poor wound healing, hair loss, diarrhea, skin irritation, smelly feet, and overall compromised immune function, impaired taste and smell. Seen in patients with poor appetites and who have chronic wounds. Vitamin and mineral supplements may contain iron to zinc ratios greater than 3:1 Vegetarian diets contain less bioavailable zinc due to high phytic acid consumption. If taking dietary supplements of zinc do so separately from iron supplements. The greatest food source is meat. Seafood particularly oyster.

Kashin-Bek Disease

Results in chronic arthritis and join deformity. Selenium deficiency.

Iron

Serves as the functional part of hemoglobin. Iron is necessary for glucose metabolism, antibody production, drug detoxification by the liver, collagen, and purine synthesis, and the conversion of b carotene to active vitamin a. The average iron intake of women is 13.6mg/day Iron deficiency anemia is most prevalent nutrition problem in the world today. Cause of iron deficiency anemia are: Inadequate dietary intake Excessive blood loss Lack of gastric hydrochloric acid Presence of inhibitors of iron absorption Leaky gut. Iron overdose from supplements is one of the leading causes of poisoning among young children who are less than 6 years old. Symptoms include nausea, diarrhea, vomiting. The UL for iron is 40mg for children birth to 18 and 45mg/day for adults. Food sources-Meat, eggs, fortified cereals. Deficiency is increased for women of childbearing age, people who are food insecure, alcohol dependent, vegetarians, elderly.

Mineral Supplementation

Special needs during growth periods and in clinical situations may merit specific mineral supplements. Diuretics- The minerals that are usually excreted with excess water are sodium, potassium, magnesium, and zinc. Chelating agents used to remove excess metal ions. Antacids- When this environment is altered as a result of chronic use of antacids mineral deficiency can occur.

Chromium

Supplements were previously thought to reduce insulin resistance. Associated with sugar cravings.

Molybdenum

The UL is 2000mcg/day for adults due to symptoms similar to gout at very high doses.

Deficiency

The deficiency disease rickets is related to an inadequate level of vit d Hypocalcemia relative to blood phosphorus concentration results in tetany. Characterized by muscle spasms.

Requirements

The dietary reference intake for calcium should provide sufficient calcium nourishment for the body while recognizing that a lower intake may be adequate for many individuals.

Manganese

The excess manganese accumulates in the liver and central nervous system, thereby producing severe neuromuscular symptoms that are similar to those of parkinsons disease.

Nature of minerals

The mineral content of the human body is quite similar to that of the earth's crust. Of the 118 elements on the periodic table,25 are essential to human life.

Occurrence In The Body

The two basic forms in which minerals occur in the body are as free ions in body fluids and as covalently bound material that may be combined with other minerals or with organic substances.

Tissue Uptake

The uptake of some minerals into their target tissue is controlled by hormones and excess minerals are excreted into the urine. For example thyroid stimulating hormone controls the uptake of iodine from the blood into the thyroid gland depending on the amount that the thyroid gland needs to make the hormone thyroxine.

Trace Minerals

These minerals are no less important to human nutrition than the major minerals.

Functions Of Minerals

They are involved in processes of building tissue as well as activating, regulating, transmitting, and controlling metabolic processes. Sodium and potassium are key players in water balance. Calcium and phosphorus are required for osteoblasts to build bone. Iron is critical to the oxygen carrier hemoglobin. Cobalt is the active site of vitamin b12

Toxicity

Toxicity of calcium from food sources is unlikely. A tolerable upper intake level for calcium has been set at 2000 to 3000mg/day depending on age.

Mineral Metabolism

Usually controlled either at the point of intestinal absorption or at the point of tissue uptake.

Pregnancy and Lactation

Women require additional copper, iodine, magnesium, molybdenum, selenium, zinc and potentially chromium to meet the demands of rapid fetal growth during pregnancy.

Menke's disease

X-linked genetic disease of copper metabolism that currently has no treatment or cure.