Minerals, Nutrition, Vitamins, and Trace Elements Flashcards
Magnesium is the second most abundant intracellular ion with the majority residing in the ___, ___, and ___.
bone; muscle; soft tissue.
Function of Magnesium.
Acts as a cofactor for over 300 enzymes; neuromuscular activator; role in metabolic pathways.
Where is magnesium absorbed and regulated?
Absorbed within the intestines and regulated via the kidneys.
Which hormone is responsible of increased tubular reabsorption and GI absorption of magnesium?
Parathyroid Hormone (PTH).
What hormones are responsible for increasing Mg concentrations?
Aldosterone and Thyroxine.
Clinical usefulness of magnesium.
Cardiovascular, metabolic, and neuromuscular disorders.
What is the most common cause of hypomagnesemia?
Drug induced hypomagnesemia.
What are miscellaneous causes of hypomagnesemia?
Reduced magnesium intake, decreased magnesium absorption, increased renal excretion, increased endocrine excretion.
How does hypertension affect magnesium levels? Hypotension?
Hypertension - decrease
Hypotension - increase
What is the most common cause of hypermagnesemia?
Acute or chronic renal failure.
What medications may cause hypermagnesemia?
Antacids, enemas, cathartics, other therapeutics.
Decreased neuromuscular reflexes and hemostasis conditions may cause a increase in ___.
magnesium.
Reference range of magnesium.
0.63 - 1.0 mmol/L.
What are the three dyes used for colorimetric measurement of magnesium?
Formazen dye, methylthymole blue, calmagite (reddish-violet complex).
Reference method of magnesium measurement.
Atomic absorption.
The primary source of calcium in the body is held within where?
The bones.
Neuromuscular irritability may the be result of low ___.
calcium.
What is the major form of calcium?
Ionized (active) Calcium.
Free calcium is highly dependent on ___ and ___ status.
albumin; pH.
What three hormones regulate calcium?
PTH, vitamin D, and calcitonin.
As calcium increases, PTH ___.
Decreases.
The parathyroid will detect low blood calcium, which stimulates PTH. How does this process affect bone resorption, urinary loss, and vitamin D production?
Increased bone resorption; decreased urinary loss; increased vitamin D production.
The parathyroid will detect high blood calcium, which suppresses PTH. How does this process affect bone resorption, urinary loss, and vitamin D production?
Decrease bone resorption; increase urinary loss; decrease vitamin D production.
Reference range for calcium.
8.6 - 10.0 mg/dL.