Foundations of Nutrition Exam 3

What are the major minerals and what classifies them as major?

Calcium, Magnesium, Sodium, Potassium, Phosphorus, and Chloride

We require >100mg/d

What are the trace minerals and what classifies them as trace?

Copper, Manganese, iron, chromium, molybdeum, iodine, zinc, fluoride, and selenium

We require <100 mg/d

Metals are _____ions, meaning they have a ______ charge, while nonmetals are ______ions, meaning they have a ______ charge.

Metals = cations (positive)

Nonmetals = anions (negative)

What are the functions of calcium?

Bone, muscle, clotting, and cofactor for lipid digestion, insulin release, and MMP

What protein does calcium use to cross the brushborder of an enterocyte? What is required?

CaT1; Vitamin D and estradiol

What protein does calcium use to cross the basolateral membrane of an enterocyte? What does it require?

Calbindin 9K; Vitamin D

What are the main sources of Calcium?

Dairy, fortified milks, and fish

What are the RDAs for Calcium:

Women <50 =

Women >50 =

Men <70 =

Men >70 =

Women <50 = 1000mg

Women >50 = 1200mg

Men <70 = 1000mg

Men >70 = 1200mg

Why do women over 50 require more calcium?

When estrogen decreases, less CaT1 proteins are activated so it is harder for Calcium to be absorbed

What symptom is associated with hypocalcemia? What sign can be seen?

Tetany; Trousseau sign

What disease is seen with a calcium deficiency?

Osteoporosis

What is associated with calcium toxicity/hypercalcemia?

Kidney stones

What does hyperphosphatemia lead to hypocalcemia?

Phosphorus and Calcium compete for absorption

What are the functions of phosphorus?

Bone, signaling, phospholipids, and energy metabolism (ATP)

What are some sources of phosphorus

Meat, poultry, fish, eggs, and diary (animal products)

What is the main symptoms of hypophosphatemia? Why?

Weakness; Phosphorus is needed for ATP

Match the cation to its balance partner:

Sodium

Calcium

Magnesium

Potassium

What makes them balance partners?

Sodium (Na+) and Potassium (K+); Calcium (Ca2+) and Magnesium (Mg2+)

The have the same valency

What causes secondary hyperparathyroidism in relationship to phosphorus?

High P leads to low Ca2+ which triggers the release of of PTH from the parathyroid gland.

What are the functions of Magnesium?

Bone, cell replication, ATP stabilization, protein synthesis, Calcium channel blocker, and PTH secretion/release

How does hypomagnesemia lead to hypocalcemia?

Mg2+ is needed for PTH secretion. PTH is needed to bring Calcium plasma levels up

How does Magnesium act as a muscle relaxer? What is a complication of long term use to prevent preterm labor?

Acts as a protein channel blocker to prevent calcium release; more than 1 week of use can lead to decrease bone mineralization

What are the main sources of magnesium? What is the main source of magnesium in the american diet?

Nuts, seeds, and whole grains; Main source = french fries

What 2 symptoms are seen with magnesium toxicity?

Diarrhea and slurred speech

What two salt forms of magnesium are harder to absorb leading to osmotic diarrhea?

Magnesium Oxide and Magnesium Sulfate

What increases magnesium absorption?

Vitamin D, protein, and carbs

What decreases magnesium absorption?

Phytate, fiber, divalent minerals (2+), phosphorus, and fatty acids in GI tract

What are a few symptoms of hypomagnesemia?

Muscle weakness (unstable ATP), tetany (hypocalcemia), and heart issues

Who is most likely to have hypomagnesemia?

alcoholics and elderly

What are the main functions of sodium?

Fluid balance and nerve/muscle function

What are the salty the main sources of? What are they?

Sodium;

1. Bread

2. Pizza

3. Cold cuts and cured meats

4. Sandwiches and burgers

5. Canned soup

6. Tacos and burritos

What are some symptoms of hyponatremia?

Muscle cramps, nausea, vomiting, and seizures

What increases ones risk of hyponatremia?

Excessive sweating and severe trauma

What are 2 symptoms of hypernatremia?

Hypocalcemia and hypertension

How does sodium toxicity lead to hypocalemia?

Increases Ca2+ excretion via the kidneys

Who would benefit most from decreasing their sodium intake?

Those with high blood pressure and the elderly

What are the main functions of potassium?

Fluid balance, nerve/muscle function, and insulin release from the pancreas

What are some sources of potassium?

Bananas, tomato juice/paste, avocados, potatoes, squash, and cantaloupe

What mineral leads to cardiac arrhythmias with both deficiency and toxicity?

Potassium

How does hypokalemia lead to hypocalcemia?

Potassium is protective against calcium excretion in the urine, so low potassium cannot prevent the excretion

Hypokalemia is often seen in combination with which mineral deficiency?

Magnesium

Potassium supplementation is not generally recommended because it can cause ______________

Small intestinal lesions

What are the main functions of chloride?

Fluid balance, digestions (HCl), and respiration

What are the main sources of chloride?

Salt (including salty 6), processed foods, eggs, meat, and seafood

What are the symptoms of chloride deficiency?

Convulsions (due to metabolic alkalosis), weakness, and lethargy

What are the 3 iron-binding proteins? What does each one do?

Ferritin - stores iron in the SI, liver, splee, and bone marrow

Ferroportin - transports iron across basolateral membrane (SI)

Transferrin - transports iron in the plasma

Which iron-binding protein requires copper and is regulated by hecidin?

Ferroportin

What are the functions of iron?

O2 transport (via Hb), Catalase (superoxide dismutase), and cofactor for cytochromes

What are the RDAs for iron:

Men =

Women =

Pregnant women =

Vegetarians =

Men = 8 mg/d

Women = 18 mg/d

Pregnant women = 27 mg/d

Vegetarians = RDA x 1.8 mg/d

Why do vegetarians require more iron than others?

Because they are eating more iron binders which decreases absorption

Heme iron is found in _______ and is absorbed using _________. Non-heme iron is found in ________ and is absorbed using __________.

animal products; heme carrier protein 1 (HCP1); plants and supplements; divalent mineral transporter (DMT)

What are the main sources of heme iron? Non-heme iron?

Liver and organ meat; legumes, enriched grains, and veggies

What is the problem with divalent mineral transporters

All minerals with a 2+ charge compete for absorption

What enzyme digests non-heme iron by to convert the ferric (3+) form of iron into the ferrous (2+) form? What cofactor does this require?

Ferrireductase; Vitamin C

What type of iron is the most bioavailable?

Heme iron

What is the most common mineral deficiency?

Iron

What iron deficiency if found with anemia. what type of anemia is it? What are the main symptoms?

Hypochromic Microcytic anemia; Pallor and fatigue

What increases iron absorption?

Fructose and sorbitol, acids, meat, poultry, fish, and mucin

What decreases iron absorption?

Polyphenols (tea and coffee), phytate (whole grains, legumes, nuts/seeds), oxalate (spinach, tea, veggies, chocolate), phosvitin (egg yolks), Ca, Zn, Mn, Ni, and acid reducing medication

Iron levels in what part of the body dictate how much hepcidin is produced? High iron level would cause hecidin levels to __________.

Liver; increase

What are some symptoms of iron toxicity?

organ damage, shock, and metabolic acidosis

Iron supplementation decrease _________ absorption.

Zinc

What is the genetic condition called that only occurs in males and leads to iron toxicity due to the inability to excrete iron?

Hemochromatosis

Cytochromes often require what 2 minerals?

Iron and copper

What enzyme is used in the enterocyte to dissociate heme iron from the prophyrin ring?

Heme oxygenase

What are the functions of zinc?

Folate digestion, nerves, bones, immunity, Vitamin A formation, DNA/RNA/protein synthesis, protein digestion, and SOD 1 and 3

What enzyme is zinc a cofactor for that helps with bone formation?

alkaline phosphate

What enzyme is zinc a cofactor for that helps form the different types of vitamin A?

alcohol dehydrogenase

What are the main sources of zinc? Which is the major source in the american diet?

Seafood (oysters), meat (major american), dairy, legumes

Vegetarians require how much more zinc that everyone else?

1.5 times more

Excessive zinc leads to a deficiency in what?

Copper and calcium? (for sure Cu, maybe Ca2+)

What are the symptoms of zinc deficiency?

skeletal abnormalities (in kinds), dermatitis, anorexia and hypogeusia (lack of taste)

Acodermatitis enteropathica is a genetic condition that causes a decrease in zinc ____________ (absorption/excretion) leading to skin lesions that are easily infected

Absorption

Zinc toxicity is associated with what main symptom?

Metallic taste

Zinc is stored as ____________ where zinc is bound to _____________.

Metallothionein; cysteine

What are the functions of copper?

Required for ceruloplasmin (iron transport), collagen cross-linking, and SOD 1 and 3

What enzyme requires copper for collagen cross-linking?

Lysyl oxidase

What are the main sources of copper?

Liver, oysters

What genetic condition is associated with a copper deficiency?

Menkes syndrome

What are the symptoms of a copper deficiency? Which of these is the best early indicator of copper deficiency?

Depigmentation (hair and skin), bone demineralization, and neutropenia (impaired immunity)

Best early indicator = neutropenia

What genetic condition is associated with copper toxicity? What are the copper deposits in the eyes that this disease causes?

Wilson's disease; Kayser-fleischer rings

What are the symptoms of copper toxicity?

Liver damage (jaundice), kidney damage, and gastric pain

Which genetic condition associated with copper has the nickname 'Kinky-hair syndrome'?

Menkes syndrome

Where does copper accumulate in Wilson's disease?

Liver, brain, kidneys, and eyes

What are the functions of iodine?

Synthesis of thyroid hormone and fetal development (skeleton and CNS)

What are the sources of iodine? Which is the main source in the american diet?

Iodized salt, seafood, dairy, fruits and veggies (dependent on soil)

Main american diet = diary

What are goitrogens? Sources?

Proteins that bind to iodine prohibiting absorption; cabbage, kale, soy, peanuts, cauliflower

A deficiency in iodine can lead to what?

Goiter, cretinism, hypothyroidism, and impaired mental/physical development in fetus and kids

What is the #1 cause of preventable brain damage worldwide?

Iodine deficiency

How does iodine toxicity lead to hypothyroidism?

Too much iodine for the thyroid to keep up with, so it gets burnt out and stops working properly

Where is magnesium and manganese concentrated in the body?

Bone

What are the functions of manganese?

SOD2 (antioxidant), wound healing, and metabolism of carbs, amino acids, and cholesterol

What are the sources of manganese?

Shellfish, whole grains, and legumes

Manganese deficiency is associated with what symptom?

Slow growth

True or false: manganese deficiency is common and will likely be seen in practice.

False - RARE, only been seen in animals

Manganese toxicity leads to ____________-like symptoms and ___________ are most at risk for it.

Parkinson's disease; manganese miners

What enzyme if molybdenum a cofactor for? What does it do?

Xanthine oxidase; converts hypoxanthine into uric acid

What is molybdenum toxicity associated with?

Gout

What are the sources of molybdenum?

Legumes, diary, and whole grains

Molybdenum deficiency is rare and typically only seen with a genetic condition called molybdenum cofactor deficiency. What symptoms would you expect to see with this condition?

Encephalopathy and seizures (neurological issues)

What are the functions of chromium?

Insulin secretion/binding and part of GTH