Bioavailability of Single-dose Magnesium Salts

Magnesium plays a role in an array of critical body functions, controls normal adenosine triphosphate function, the metabolism of glucose, and cardiac muscle function, as well as the maintenance of cell membrane function. Low magnesium intakes and blood levels have been associated with a number of chronic diseases including hypertension, type 2 diabetes, metabolic syndrome, vascular disease, osteoporosis, and colon cancer. Magnesium deficiency is common. In the U.S. population, nearly 4% of men and 7% of women have hypomagnesemia (typically defined as a serum concentration <0.75 mmol/L, or < 17mg/L), which has been previously shown to be associated with an increased risk of all-cause mortality after 30 years of follow-up. In addition, hypomagnesemia is seen in approximately 11% of hospitalized patients and 52% of patients in coronary care units. Approximately half of the U.S. population does not currently reach the estimated average requirement (EAR) for magnesium from food. Yet magnesium deficiency is often overlooked.

Magnesium is relatively well absorbed by the gut; oral bioavailability varies from 35 to 70% and depends on a variety of factors such as the form of the magnesium salt (organic vs. inorganic), its rate and extent of uptake from the intestine into the blood, and its transfer into tissues because magnesium is primarily an intracellular cation. The absorption rate increases when dietary intake is low. In terms of the effectiveness of oral dietary supplements, bioavailability and tolerability of various formulations are important considerations. Similar bioavailability has been demonstrated between inorganic formulations (magnesium oxide vs. magnesium chloride), however some studies have shown magnesium oxide to be less bioavailable. Diarrhea and abdominal cramping are side effects that are commonly reported from oral oral supplementation. These symptoms are thought to be due to the osmotic activity of unabsorbed salts in the intestine and colon and the stimulation of gastric motility. A new picometer-ionic form of magnesium chloride, was developed to efficiently deliver stabilized magnesium ions that are similar in size to plant magnesium. Picometer magnesium is smaller in diameter than the body's cell mineral ion channels, therefore it has the potential to be completely absorbed and not cause adverse side effects in the gastrointestinal system (e.g., diarrhea). The aim of this research is to assess the bioavailability of this new picometer-ionic form of magnesium chloride by comparing its bioavailability to that of a standard magnesium oxide and magnesium citrate supplement in healthy, adult, normotensive subjects.