Minerals, Nutrition, Vitamins, and Trace Elements

Question 1

Magnesium is the second most abundant intracellular ion with the majority residing in the ___, ___, and ___.

Answer 1

bone; muscle; soft tissue.

Question 2

Function of Magnesium.

Answer 2

Acts as a cofactor for over 300 enzymes; neuromuscular activator; role in metabolic pathways.

Question 3

Where is magnesium absorbed and regulated?

Answer 3

Absorbed within the intestines and regulated via the kidneys.

Question 4

Which hormone is responsible of increased tubular reabsorption and GI absorption of magnesium?

Answer 4

Parathyroid Hormone (PTH).

Question 5

What hormones are responsible for increasing Mg concentrations?

Answer 5

Aldosterone and Thyroxine.

Question 6

Clinical usefulness of magnesium.

Answer 6

Cardiovascular, metabolic, and neuromuscular disorders.

Question 7

What is the most common cause of hypomagnesemia?

Answer 7

Drug induced hypomagnesemia.

Question 8

What are miscellaneous causes of hypomagnesemia?

Answer 8

Reduced magnesium intake, decreased magnesium absorption, increased renal excretion, increased endocrine excretion.

Question 9

How does hypertension affect magnesium levels? Hypotension?

Answer 9

Hypertension - decrease

Hypotension - increase

Question 10

What is the most common cause of hypermagnesemia?

Answer 10

Acute or chronic renal failure.

Question 11

What medications may cause hypermagnesemia?

Answer 11

Antacids, enemas, cathartics, other therapeutics.

Question 12

Decreased neuromuscular reflexes and hemostasis conditions may cause a increase in ___.

Answer 12

magnesium.

Question 13

Reference range of magnesium.

Answer 13

0.63 - 1.0 mmol/L.

Question 14

What are the three dyes used for colorimetric measurement of magnesium?

Answer 14

Formazen dye, methylthymole blue, calmagite (reddish-violet complex).

Question 15

Reference method of magnesium measurement.

Answer 15

Atomic absorption.

Question 16

The primary source of calcium in the body is held within where?

Answer 16

The bones.

Question 17

Neuromuscular irritability may the be result of low ___.

Answer 17

calcium.

Question 18

What is the major form of calcium?

Answer 18

Ionized (active) Calcium.

Question 19

Free calcium is highly dependent on ___ and ___ status.

Answer 19

albumin; pH.

Question 20

What three hormones regulate calcium?

Answer 20

PTH, vitamin D, and calcitonin.

Question 21

As calcium increases, PTH ___.

Answer 21

Decreases.

Question 22

The parathyroid will detect low blood calcium, which stimulates PTH. How does this process affect bone resorption, urinary loss, and vitamin D production?

Answer 22

Increased bone resorption; decreased urinary loss; increased vitamin D production.

Question 23

The parathyroid will detect high blood calcium, which suppresses PTH. How does this process affect bone resorption, urinary loss, and vitamin D production?

Answer 23

Decrease bone resorption; increase urinary loss; decrease vitamin D production.

Question 24

Reference range for calcium.

Answer 24

8.6 - 10.0 mg/dL.

Question 25

Critical values of calcium.

Answer 25

<6 or >14 mg/dL.

Question 26

How does acute pancreatitis and vitamin D deficiency affect calcium?

Answer 26

Low calcium levels.

Question 27

Symptoms of hypocalcemia.

Answer 27

Neuromuscule irritability, CNS changes, cardiac changes.

Question 28

What is the most common condition for hypercalcemia?

Answer 28

Primary hyperparathyroidism - caused by tumor producing PTH.

Question 29

Which body systems would be affected by an increased calcium?

Answer 29

Neurologic, GI, Renal, Skeletal, Cardiovascular.

Question 30

What method is used for calcium measurement?

Answer 30

Colorometric: dye binding.

Question 31

Reference method to measure calcium.

Answer 31

Atomic absorption.

Question 32

What are specimen requirements for calcium testing?

Answer 32

Whole blood collected anaerobically in heparinized tube.

Question 33

How would air exposure affect calcium testing?

Answer 33

pCO2 and H decreases, resulting in decreased calcium.

Question 34

What is defined as the major intracellular anion?

Answer 34

Phosphorus.

Question 35

PTH ___ calcium and ___ phosphorus.

Answer 35

increases; decreases.

Question 36

Vitamin D ___ calcium and ___ phosphorous.

Answer 36

increases; increases.

Question 37

Growth hormone ___ phosphorus.

Answer 37

Increases.

Question 38

Reference range of phosphorous.

Answer 38

2.4 - 4.4 mg/dL.

Question 39

What are some conditions that can result from hypophosphatemia?

Answer 39

Hyperparathyroidism, vitamin D deficiency, decreased intestinal absorption, and increased renal excretion.

Question 40

What are common diseases where hypophosphatemia may occur?

Answer 40

DKA, COPD, TPN treatment, malignancy.

Question 41

What are common diseases where hyperphosphatemia may occur?

Answer 41

Acute/chronic renal failure, hypoparathyroidism, chemotherapy, vitamin D toxicity, and intravascular hemolysis.

Question 42

What is the ideal specimen for phosphorus testing?

Answer 42

Serum or lithium heparin plasma.

Question 43

Phosphorus undergoes ___ making it elevated in the AM and low in the PM.

Answer 43

Circadian Rhythm.

Question 44

What testing method is used for phosphorus testing?

Answer 44

Colorimetric.

Question 45

Bone turnover-remodeling is regulated what hormones?

Answer 45

PTH and Vitamin D.

Question 46

What analytes can be used to assess bone function?

Answer 46

Vitamin D, PTH, Calcium, Magnesium, Phosphate.

Question 47

Calcitonin is a tumor marker for ___.

Answer 47

Thyroid.

Question 48

Why is it not unusual for ALP to be elevated in children?

Answer 48

Due to bone development.

Question 49

Describe Osteopenia.

Answer 49

A condition that begins as you lose bone mass and your bones get weaker.

Question 50

Describe osteoporosis.

Answer 50

Decreased bone mass due to aging.

Question 51

Describe osteomalacia.

Answer 51

Decreased mineralization in the bone; can be caused by Rickets in children or Vitamin D deficiency.

Question 52

Describe Osteitis fibrosa.

Answer 52

Increased bone reabsorption; histopathological bone lesion. Can be common in hyperparathyroidism and renal failure.

Question 53

Describe Paget's Disease.

Answer 53

Increased osteoclastic activity resulting in disordered, excessive osteoblastic activity.

Question 54

What analytes are elevated in Paget's Disease?

Answer 54

Calcium and ALP.

Question 55

Describe osteogenesis imperfecta.

Answer 55

An inherited condition that may lead to low bone mass and fractures due to collagen defects.

Question 56

What biochemical assessment markers can be used to assess nutrition levels?

Answer 56

Macronutrients: carbohydrates, proteins, fats Micronutrients: minerals, vitamins, trace elements

Question 57

A decreased albumin level in a patient with known lack of nutrition indicates what?

Answer 57

Patient is in a starvation mode for low protein state for a long period of time.

Question 58

What are the fat soluble vitamins?

Answer 58

Vitamin A, E, K, and D.

Question 59

What are the water soluble vitamins?

Answer 59

Vitamin B complexes, Vitamin C, and carnitine.

Question 60

Vitamin A (retinol) function.

Answer 60

Vision; growth, reproduction, and immunity.