Lavigna, Robin. Magnesium. KNH 413 – Medical Nutrition Therapy II. Miami
University, Oxford, Ohio, Spring 2013.
Magnesium
1. What is the nutrient?
Magnesium
2. What is the RDA/DRI for the nutrient?
3. How is the nutrient metabolized?
It is mostly absorbed in the upper small intestine, 50% of dietary magnesium
is absorbed in a normal person. Absorption of magnesium requires an acidic
stomach. It is secreted by the kidneys.
4. What are food sources of the nutrient?
Dark green vegetables such as spinach, some legumes, nuts and seeds, and
whole unrefined grains (with bran), and even “hard” water are good sources
of magnesium. Some examples of foods include: wheat bran almonds,
spinach, cashews, soy beans, mixed nuts, oatmeal, shredded wheat, peanuts
and peanut butter, potato, rice, pinto beans, lentils, banana, yogurt, and
halibut.
5. What disease states alter the nutrients metabolism?
Gastrointestinal disorders that impair absorption such as Crohn’s disease
alter the metabolism of magnesium. Chronic or excessive vomiting and
diarrhea can also alter the state. Addison’s disease, chronic renal failure,
dehydration, and diabetic acidosis can cause high levels of magnesium.
Alcoholism, hemodialysis, cirrhosis of the liver, pancreatitis, and too much
insulin can cause low levels of magnesium.
6. What are the tests or procedures to assess the
nutrient level in the body?
Blood tests are usually taken to assess the levels of magnesium in the body
(serum magnesium test). Levels tend to be checked when other levels are
being checked for certain diseases like diabetes or kidney problems.
7. What is the drug –nutrient interactions?
Diuretics can increase the loss of magnesium in the urine. Some laxatives
and antacids contain magnesium, when taken in large doses this can lead to
excessive consumption.
8. How is the nutrient measured?
When levels are taken with a blood test magnesium is measured in mg/dL.
9. What is the Upper Tolerable Limits?
10.What are the physical signs of deficiency?
Loss of appetite, nausea, vomiting, fatigue, and weakness. As it worsens,
numbness, tingling, muscle contractions and cramps, seizures, personality
changes, abnormal heart rhythms, and coronary spasms. Severe deficiency can
result in low levels of calcium and potassium in the blood.
11.What are physical signs of toxicity?
Dietary intake doesn’t result in toxicity, but pharmacological doses of
magnesium can result in diarrhea and abdominal cramping. Risk for toxicity
increases with kidney failure. Signs include changes in mental status, nausea,
diarrhea, appetite loss, muscle weakness, difficulty breathing, extremely low blood
pressure, and irregular heartbeats.