Magnesium absorption, intestinal

Studies in humans have indicated that increasing the level of dietary protein enhances magnesium absorption [40,41]. Excessive dietary fat has been shown to impair magnesium absorption due to the formation of insoluble magnesium soaps [42,43]. Readily available carbohydrates such as lactose may enhance magnesium intestinal absorption [44,45], while excess dietary fiber may decrease magnesium absorption in humans [46]. The ionophores monensin and lasalocid have both been shown to enhance magnesium absorption in steers [47). 

Calcium (Ca ) Parathyroid hormone Calcitonin Magnesium (helps in calcium metabolism and intestinal absorption) Intestinal absorption Renal reabsorption Renal excretion... 

Magnesium (Mg ) Intestinal absorption Renal reabsorption Renal excretion... 

Minerals May increase calcium and magnesium absorption in large intestine... 

Treatment. Treatment of poisoning from soluble barium salts may be preventive or curative (47,51). Preventive treatment involves inhibition of intestinal absorption by administering such soluble sulfates as magnesium or sodium, causing precipitation of barium sulfate in the alimentary tract. 

Most of the interactions with mycophenolate mofetil and enteric-coated MPA are due to reductions in intestinal absorption. Aluminum-, magnesium-, or calcium-containing antacids decrease the peak level and overall exposure of MPA from either of the preparations.11 If a patient requires liquid antacids, they should be administered at least 4 hours before... 

Hypomagnesemia is usually associated with disorders of the intestinal tract or kidneys. Drugs (e.g., aminoglycosides, amphotericin B, cyclosporine, diuretics, digitalis, cisplatin) or conditions that interfere with intestinal absorption or increase renal excretion of magnesium can cause hypomagnesemia. 

These studies have shown that phosphorus, magnesium and fluoride In the doses used had no effect on the bloavailablllty of calcium, while large doses of zinc given during a low calcium Intake Inhibited the Intestinal absorption of calcium The effect of protein and of certain drugs on calcium metabolism Is also described ... 

These antibiotics are partially absorbed from the stomach and upper gastrointestinal tract. Food impairs absorption of all tetracyclines except doxycycline and minocycline. Absorption of doxycycline and minocy-cbne is improved with food. Since the tetracyclines form insoluble chelates with calcium (such as are found in many antacids), magnesium, and other metal ions, their simultaneous administration with milk (calcium), magnesium hydroxide, aluminum hydroxide, or iron will interfere with absorption. Because some of the tetracyclines are not completely absorbed, any drug remaining in the intestine may inhibit sensitive intestinal microorganisms and alter the normal intestinal flora. 

Mechanism of Action A nonabsorbable compound that alters urinary composition of calcium, magnesium, phosphate, and oxalate. Calcium binds to cellulose sodium phosphate, thus preventing intestinal absorption of it. Therapeutic Effect Prevents the formation of kidney stones. 

Contraindications Primary or secondary hyperparathyroidism, including hypercalci-uria (renal calcium leak), hypomagnesemic states (serum magnesium less than 1.5 mg/dl), bone disease (osteoporosis, osteomalacia, osteitis), hypocalcemic states (e.g., hypoparathyroidism, intestinal malabsorption), normal or low intestinal absorption and renal excretion of calcium, enteric hyperoxaluria, and patients with high fasting urinary calcium or hypophosphatemia. 

Kobayashi, A., Kawai, S., Ohbe, Y. and Nagashima, Y. 1975. Effects of dietary lactose and a lactase preparation on the intestinal absorption of calcium and magnesium in normal infants. Am J. Clin. Nutr. 28, 681-683. 

Antacid preparations based on aluminium hydroxide sometimes contain magnesium salts (and carbonate or oxide) to offset the constipating effect of the alumina. This laxative effect of salts such as magnesium sulphate (or citrate) and other saline cathartics such as potassium sodium tartrate is due to their incomplete absorption from the digestive tract so that, by osmotic forces, they retain water in the intestinal lumen. 

Coudray, C., Tressol, J.C., Gueux, E., and Rayssinguier, Y., Effects of inulin-type fructans of different chain length and type of branching on intestinal absorption of calcium and magnesium in rats, Eur. J. Nutr., 42, 91-98, 2003. 

Vitamin Bj Vitamin Bj was discovered in 1926 by Jansen and Do-NATH, who synthesized it in its crystalline form from rice bran. It was initially called aneurine due to its antipolyneuropathic effect. Because it contains sulphur, Windaus correctly renamed it thiamine in 1932, a term by which it is still known today. The stixicture of this vitamin was described by Williams and Grewe in 1936. It is made up of pyrimidine and thiazole. Thiamine occurs in nature as free thiamine and in the form of thiamine monophosphate, diphosphate and triphosphate. A maximum amount of 8 — 15 mg is absorbed daily in the proximal portion of the small intestine. In the case of oversupply, thiamine is neither stored nor intestinally absorbed. A regular intake, with a daily requirement of about 1 mg, is necessary. The major coenzyme is thiamine pyrophosphate (TPP). Thiamine deficiency may be caused by malnutrition, impaired absorption, alcoholism, antithiamines or a lack of magnesium. Magnesium is an important cofactor for the coenzyme thiamine pyrophosphate. 

---