Neurological effects
reducing electrical excitation
modulating release of acetylcholine
antagonising N-methyl-D-aspartate (NMDA) glutamate receptors, an excitatory neurotransmitter of the central nervous system and thus providing neuroprotection from excitoxicity. Diabetes mellitus
Magnesium deficiency is frequently observed in people with type 2 diabetes mellitus, with an estimated prevalence ranging between 11.0 and 47.7%. Magnesium deficiency is strongly associated with high glucose and insulin resistance, which indicate that it is common in poorly controlled diabetes. Patients with type 2 diabetes and a magnesium deficiency have a higher risk of heart failure, atrial fibrillation and microvascular complications. Oral magnesium supplements has been demonstrated to improve insulin sensitivity and lipid profile. However, their effect on cardiovascular risk in diabetes are to be determined. Homeostasis
Magnesium is abundant in nature. It can be found in green vegetables, chlorophyll (chloroplasts), cocoa derivatives, nuts, wheat, seafood, and meat. It is absorbed primarily in the duodenum of the small intestine. The rectum and sigmoid colon can absorb magnesium. Forty percent of dietary magnesium is absorbed. Hypomagnesemia stimulates and hypermagnesemia inhibits this absorption.The body contains 21–28 grams of magnesium (0.864–1.152 mol). Of this, 53% is located in bone, 19% in non-muscular tissue, and 1% in extracellular fluid. For this reason, blood levels of magnesium are not an adequate means of establishing the total amount of available magnesium.The majority of serum magnesium is bound to chelators, including proteins and citrate. Roughly 33% is bound to proteins, and 5–10% is not bound. This "free" magnesium is essential in regulating intracellular magnesium. Normal plasma Mg is 1.7–2.3 mg/dL (0.69–0.94 mmol/L).
Replacement by mouth is appropriate for people with mild symptoms, while intravenous replacement is recommended for people with severe effects.Numerous oral magnesium preparations are available. In two trials of magnesium oxide, one of the most common forms in magnesium dietary supplements because of its high magnesium content per weight, was less bioavailable than magnesium citrate, chloride, lactate or aspartate. Magnesium citrate has been reported as more bioavailable than oxide or amino-acid chelate forms.Intravenous magnesium sulfate (MgSO4) can be given in response to heart arrhythmias to correct for hypokalemia, preventing pre-eclampsia, and has been suggested as having a potential use in asthma. Food
Food sources of magnesium include leafy green vegetables, beans, nuts, and seeds. Epidemiology
The condition is relatively common among people in hospital. History
Magnesium deficiency in humans was first described in the medical literature in 1934. Plants
Magnesium deficiency is a detrimental plant disorder that occurs most often in strongly acidic, light, sandy soils, where magnesium can be easily leached away. Magnesium is an essential macronutrient constituting 0.2-0.4% of plants dry matter and is necessary for normal plant growth. Excess potassium, generally due to fertilizers, further aggravates the stress from magnesium deficiency, as does aluminium toxicity.Magnesium has an important role in photosynthesis because it forms the central atom of chlorophyll. Therefore, without sufficient amounts of magnesium, plants begin to degrade the chlorophyll in the old leaves. This causes the main symptom of magnesium deficiency, interveinal chlorosis, or yellowing between leaf veins, which stay green, giving the leaves a marbled appearance.