Download Major Minerals: Chapter 8 What are minerals? Calcium: -

Major Minerals: Chapter 8
What are minerals?
Calcium:
--most abundant of body minerals. 99% is located in bones and teeth
Roles:
  Food sources:
Ca role in body fluids:
Regulates transport of ions across cell membranes and has an important role in nerve transmission.
 Maintenance of normal blood pressure.
 Essential role in blood clotting.
 Essential for muscle contraction and heartbeat.
 Allows secretions of hormones, digestive enzymes and neurotransmitters.
 Activates cellular enzymes that regulate many processes.
Serum levels of Ca:
 Are tightly controlled within narrow limits.
 Levels are controlled by hormones and not dietary intake.
Calcium needs change throughout the life cycle:
Terms to know:
Peak Bone Mass:
Osteoporosis/ osteopenia/ ostemalacia:
Adult Bone loss:
Connection with Vit D:
Phosphorus:
2nd most abundant, found in bones.
Roles of phosphorus:
      Animal products are the best sources and phosphorus is widespread in the diet.
Deficiency is unknown.
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Magnesium:
Found in mainly in bones with the remainder in soft tissues, including muscle, heart, liver and kidneys.
Roles of Magnesium:
       Most Americans do not get the RDA:
  Deficiencies occur due to Vomiting, inadequate intake, diarrhea, alcoholism, and protein malnutrition.
Magnesium may have a role in the prevention of heart disease, heart attack and HTN.
Toxicity is rare, but can be fatal, primarily from supplements, laxatives, antacids, and other medications. Care
must be taken with long-term heavy use of magnesium containing medications.
Sodium:
1gram of table salt (Sodium chloride) contains 400mg of sodium
Required for proper fluid and electrolyte balance. It is stored on the surface of bone crystals, which can be
mobilized in the event of low serum concentrations.
Deficiency is unknown. All diets contain sodium from natural and sodium-added foods. Body can absorb the
amount needed for proper functioning and the kidneys filter excessive salt out of serum and it is excreted in urine.
Salty foods trigger thirst which will help the body to dilute the sodium in the blood and normalize serum levels.
Some small amounts are lost in sweat.
Recommendations for sodium intake:
 DRI for adults is 1,500mg, 1300mg for 51-70 and 1200mg for the elderly.
 The upper limit of sodium intake is 2,300mg/day; Average consumption is 3,300mg/day.
Low-sodium diets:
 Appropriate for HTN.
 The more salt a person eats the more blood pressure goes up for those who are salt-sensitive. These
populations include African Americas, those with family history of HTN and those over the age of 50.
 Genetics play a large role in the degree of salt-sensitivity.
 DASH (Dietary Approaches to Stopping Hypertension) diet: similar to the Mediterranean diet with a
focus on fruits, vegetables, whole grains, lean meats, fish and healthy fats.
Dangers of uncontrolled HTN:
 Increased risk for stroke.
 Cardiovascular disease and artery damage
 Heart attack.
 Organ damage (kidneys)
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Potassium:
Principal positive ion inside cells (Sodium-Potassium Pump)
Roles of Potassium in the body:
   Dehydration causes the loss of potassium and the person will not feel the thirst sensation and can lose important
cellular function. This is one of the problems seen in the use of diuretics, as a result there are Potassium sparing
diuretics that help to overcome this problem.
A well-balanced diet with fruits and vegetables will provide adequate intake of potassium, however, the average
American does not get the RDA of potassium. Whole foods are good sources (potatoes, bananas and beans).
Low potassium intake is associated with:
 Worsening of HTN.
 Glucose tolerance is impaired.
 Metabolic acidity increases.
 Calcium can be lost from bones and teeth.
 Kidney store formation is more likely.
Chloride:
Chloride is the major negatively charged ion in the body.
Role of Chloride:
 Maintains critical fluid balances—acid-base and electrolyte.
 Part of hydrochloric acid, a major component of stomach acid and aids in the breakdown of proteins.
Table salt is the main source of chloride in the diet and deficiency is highly unlikely.
Trace Minerals:
Iodine:
Iodine is found in the body as a component of thyroxine, the hormone made by the thyroid gland.
The thyroid is one of the largest endocrine glands in the body. This gland is found in the neck. The thyroid
controls how quickly the body burns energy and makes proteins.
Deficiency:
 Goiter, enlargement of the thyroid gland in body’s attempt to absorb more iodine from the serum.
 People gain weight and become sluggish.
 During pregnancy, deficiency can result in mental and physical retardation, called cretinism.
 This is the most common and preventable causes of mental retardation worldwide.
 To combat deficiency, many foods are fortified with iodine, salt in the US, milk in UK.
Iodine in the diet is dependant on:
 The soil where crops are grown and roximity to the ocean and intake of seafood and fish.
 Supplemented foods.
 In the US, the main source in the diet is from salt, which is iodized—although not all salt in the US is.
Those exposed to nuclear contamination and radioactive iodine, are often treated with potassium iodide to prevent
damage to the thyroid gland.
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Iron:
Found in the body in two forms:
 Hemoglobin—
 Myoglobin—
Iron Regulation in the body:
 Iron is tightly regulated and conserved in the body. Red blood cells (RBCs), which contain a large
portion of the body storage, live about 120 days. After their cellular death, the iron is recycled from these
old RBCs and is used to make new cells. Bleeding can lead to significant losses of iron.
 When iron is low, the body is able to increase the amount absorbed from the diet to meet needs.
 Once absorbed by the body, iron is difficult to excrete.
 Iron absorption cell regulation has a genetic component.
Deficiency:
 Iron deficiency: depleted iron stores, which can cause iron-deficient anemia.
 Iron-deficient anemia: depleted iron stores that do not allow the production of normal cells with the
correct amount of iron, resulting in low levels of hemoglobin in RBCs.
 Symptoms of deficiency can include; tiredness, fatigue, tendency to feel cold, inability to concentrate,
poor mood, apathy.
Causes of iron deficiency:
 Diet that lacks in iron containing food.
 Malnutrition.
 Blood loss—especially with women.
 Digestive problems.
 Infections and parasites.
What is pica and what could it mean?
Iron overload: (hyperchromatosis)
 Iron is a powerful oxidant and can cause cellular damage—this is one reason that men with a high intake
of iron are at greater risk of heart disease.
 Strong genetic component. Tends to run in families.
 Overuse of supplements –one of the most common causes of poisoning deaths in children.
Iron Recommendations:
Men: 8mg/day
Women: 19-50 = 18mg/day
Women: 51+ = 8mg/day
Vegetarians:
Normal needs for their age x 1.8 = intake requirements
 Heme iron—in animal products iron is complexed with heme, which makes the iron more readily
absorbed by the body
 Non-heme iron—generally found in non-animal sources, and absorbed at a reduced rate.
MFP factor: a factor present in meat, fish and poultry that enhances the absorption of non-heme iron. Cooking
acidic foods in cast-iron pans can increase intake.
Factors that reduce or block absorption:
 Phytates: a compound found in plants and some grain products.
 Tannins: compounds in black tea.
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Zinc:
Required in small amounts.
It has a role in:
 Synthesis of cellular genetic material.
 Production of heme (RBCs).
 Assists the pancreas with digestive functions.
 Metabolizes energy-yielding nutrients.
 Mobilizes stored vitamin A from the liver.
 Promotes healthy immune system.
 Has a role in the promotion of fertility.
Deficiency is more common than overload. Toxicity is seen mainly with supplement use and can interfere with
copper andiron absorption.
Selenium:
 Role in the body:
 Protective as an anti-oxidant.
 Implicated in immune function.
 Activated thyroid hormone, which regulates metabolism.
 Low-levels are thought to increase certain types of cancer—esp. prostate.
 Deficiency contributes to the development of certain types of heart disease.
Toxicity:
 Depends on location and the soil in which crops are grown, ie. Dakotas in US and China.
 Supplements.
Fluoride:
Essential for life, but also for bone and dental health.
Role in body:
  Sources in the diet:
 Fluoridated water.
 Medications (fluoride drops for children).
 Tooth paste.
Toxicity:
 Fluorosis:
Chromium:
Role in the body:
 Regulates insulin.
 Involved in the production of energy from glucose.
Diets high in simple sugars and low in whole foods can deplete the body’s stores. Chromium can be lost during
food processing.
Supplements do not increase muscle mass and should not be used for this purpose.
Does not lower serum cholesterol levels.
Exposure to toxic levels can increase cancer risk, especially in industrial settings.
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Copper:
Role in the body:
 Helps in the formation of hemoglobin and collagen.
 Processing and handling of iron.
 Reduces free-radical activity and potential cellular damage.
Deficiency:
Impaired immunity, bone abnormalities, anemia.
Toxicity: Interferes with iron absorption, diarrhea, liver damage.
Sulfate:
Found in protein containing foods:
Role in the body:
 Toxicity:
Deficiency:
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