Chapter 7 - Minerals

Essentials of Nutrition & Diet Therapy - Chapter 7 (Minerals) review

What is Bioavailability?

A portion of an ingested nutrient that is absorbed and can be used in carrying out body functions

What are the trace elements?

Iron, Iodine, Zinc, Copper, Manganese, Chromium, Selenium, Molybdenum, Fluoride

Which nutrient must be supplied by food because it’s not made in the body?

Minerals

What are minerals?

Simple elements with important roles in both structure and function.

What are the 4 forms of Iron?

Transport Iron, Hemoglobin & myoglobin, Storage Iron and Cellular Iron.

How is Iron excreted?

In the feces

Where is Iron balance controlled?

At the absorption site in the small intestine.

What are the 2 forms of dietary iron?

Heme Iron & Nonheme Iron

What food sources is Heme Iron found?

Only meat, fish, poultry

Where is nonheme iron found?

In both plant tissue and animal tissue

Which form of iron is absorbed less efficiently?

Nonheme

Which form of iron are Vegans more deficient?

Heme

What are the 3 factors of iron absorption?

Body need, Ascorbic Acid (vit C or other acids), Animal tissue

What is required to reduce iron to ferrous form?

Gastric Acid

Ferric Iron (Fe³⁺) must be reduced to what before it can be absorbed?

Ferrous Form (Fe²⁺)

Who needs more iron?

Vegetarians

Which mineral is a component of thyroxine produced in the thyroid gland?

Iodine

Where is Iodine absorbed?

Small intestine in the form of iodides

What happens to Iodides?

They are loosely bound to proteins and carried by the blood to the thyroid gland

Where is absorbed iodide that’s not needed by the thyroid gland excreted?

In the urine

Why does TSH direct uptake of iodine by thyroid cells?

In response to plasma thyroid hormone levels

What is the major function of Iodine?

The synthesis of the thyroid hormone thyroxine.

What does Thyroxine do?

It regulates cell oxidation and Basal metabolic rate (BMR)

What is hyperthyroidism?

Very active thyroid function

What is hypothyroidism?

Not very active thyroid function

What is Plasma Thyroxine?

Free thyroxine secreted into the bloodstream and bound to plasma protein for transport to cells.

What happens to Plasma Thyroxine after completing its work?

The hormone is degraded in the liver and excreted in the bile.

What is a goiter?

Visible enlargement of the thyroid gland

What is Cretinism?

The result of severe iodine deficiency during critical brain development that causes irreversible mental retardation and disability

Where is soil that contains higher amounts of Iodine?

Near the ocean/sea

Iodized table salt is fortified with how many grams per 10g of salt?

1mg of Iodine

What type of food is rich in Iodine?

Seafood

Where is Zinc present?

In small quantities in all body organs, tissues, fluids and secretions.

When is Zinc especially important?

Periods of rapid growth

What interferes with Zinc absorption?

Phytates in plant foods

What processes is Zinc closely involved with?

DNA & RNA metabolism and Protein synthesis

Where is Zinc stored primarily?

in muscle and bone

Where is Zinc absorbed?

Midsection of the small intestine

Where is Zinc excreted?

in the feces

What are the clinical problems stemming from Zinc deficiency?

Hypogonadism, Loss of taste & smell, impaired wound healing, impaired growth & development, Malabsorption, impaired immune function

Zinc supplements interfere with the absorption of what 2 minerals?

Iron and Copper

What supplement may interfere with Zinc absorption?

Iron

What are good sources of Zinc?

Seafood (especially oysters), meat, eggs, milk.

legumes and whole grains are less rich

What is the most abundant intercellular trace element?

Zinc

When is Zinc toxic?

When taken in excess

Which 2 minerals are components of cell enzymes, involved in energy production and participate in hemoglobin synthesis?

Iron and Copper

What are the richer sources of Copper?

Liver, seafood, nuts and seeds

What mineral can decrease the bioavailability of Copper?

Zinc

What is an excellent source of Chromium?

Brewer’s Yeast

Where is Chromium found in the body?

Minute amounts in liver, soft tissues and bone.

Which mineral that facilitates action of insulin and assists in moving glucose into cells?

Chromium

Where in the body is Selenium concentrations highest?

liver, kidney, heart and spleen

What mineral is an integral part of an antioxidant enzyme that protects cells & lipid membranes from oxidative damage?

Selenium

Selenium is deposited in all body tissue except which?

Adipose tissue

What Vitamin spares Selenium?

Vitamin E

What are good sources of Selenium?

Seafood, legumes, whole grains, lean meats, dairy products

Where do we get the most consistent amount of Fluoride?

Toothpaste

Where does Fluoride accumulate in the body?

In the calcified tissues

What does Fluoride do?

Protects bones and teeth from mineral loss (resorption), prevents against dental caries.

What are food sources of Fluoride?

Fish, fish products, tea

What can excess Fluoride lead to?

pitted and discolored teeth

Cobalt is apart of what Vitamin?

B12

Where is Cobalt found in our body?

Found in small amounts in body tissue

Where is Cobalt stored?

The liver

What is a function of Cobalt?

RBC support of myelin sheaths surrounding nerve fibers in the central nervous system

Who has more body water?

Men - 55-60%

What is the function of water in the body?

Provides form and structure, it’s a fluid environment for chemical reactions, Helps control body temperature, acts as lubricant and cushion around joints, dissolves important substances in tissue and cells, fluid to dissolve medication, maintains blood volume, acts as vehicle for elimination of waste, acts as shock absorber inside eyes, spinal cord and in pregnancy (amniotic sac)

How does water leave the body?

kidneys, skin, lungs, feces

Which group is most at risk for dehydration?

Older Adults

What Clinical situations influence water needs?

Uncontrolled Diabetes

Cystic Fibrosis

High Fiber intake

High Protein intake

What are the 2 major compartments water is divided into?

Water outside the cells (ECF compartment)

Water inside the cells (ICF compartment)

What influences the movement of water in and out of the capillaries?

Albumin & Globulin

What helps maintain blood volume?

Exert colloidal osmotic pressure

What organic compounds are important in water distribution in the body?

Glucose, urea and amino acids. In large concentrations.

What determines the chemical combining power of electrolytes?

The number of particles - NOT size

What must stable solutions have to be electrically neutral?

Equal numbers of positive and negative particles

What is the chief cation of ECF?

Sodium

What is the chief cation of ICFV (intracellular fluid volume)

Potassium

What are the 2 opposing pressures that control movement of water and solute across capillary membranes?

Hydrostatic pressure (BP)

Colloid osmotic pressure from plasma membranes

What forces water and small solutes into the tissues from the capillaries?

Blood Pressure

What causes edema?

Low serum albumin

What guards water within the cell?

Ionized Potassium

What guards water outside the cell?

Ionized Sodium

What does ADH (Anti-diuretic hormone) Vasopressin do?

Controls water reabsorption in kidneys

Why is ADH - Vasopressin secreted?

in response to increase in concentration of particles in the ECF or decreased blood volume and Blood pressure.

When do ADH levels rise?

With loss due to sweating, fever or major blood loss.

What is aldosterone?

A Sodium conserving hormone associated with renin-angiotensin-aldosterone system

What systems work together to cooperatively maintain normal hydration?

ADH & Aldosterone

How are the ADH and Aldosterone systems activated?

injury, surgery, vomiting, diarrhea or other physiologic stress that causes loss of body water

How much water does an adult metabolize a day?

2.5-3 liters

What are DRIs for minerals expressed as?

RDA, EAR, AI

What decreases Mineral bioavailability absorption?

Oxalates - Plants

Phytates - grains, nuts

Phosphates- brown rice

What increases bioavailability absorption?

Gastric acidity

Chemical form of mineral

Other foods at same meal

Body need

What is the Iron containing component in blood?

Hemoglobin

What minerals help decrease blood pressure levels?

Potassium and Magnesium

Diarrhea and vomiting result in significant losses of what mineral?

Potassium

Who is at highest risk for iron deficiency anemia?

Vegetarian teenage girls

Where is iron from diet absorbed?

The intestinal mucosal cells

What are minerals?

Simple elements with important roles in both structure and function that are needed in small amounts

What are major minerals?

Minerals that are needed in the diet in amounts greater than 100mg/d OR are present in the body in amounts greater than 0.01% of body weight.