When choosing a magnesium supplement, the amount of elemental magnesium on the label is only part of the story. The form of magnesium matters, because different magnesium compounds have different solubility, behaviour in the stomach and bioavailability.
Shifa Triple Magnesium Powder provides 300 mg elemental magnesium per serving from three carefully selected forms:
Magnesium Bisglycinate • Magnesium Citrate • Magnesium Malate
Rather than relying on magnesium oxide or magnesium carbonate, our formula combines three organic/chelated forms selected for their favourable absorption characteristics.
Magnesium Forms Compared
| Magnesium Form | Type | Behaviour in the Stomach | Human Bioavailability | Serum Magnesium AUC* | Key Consideration |
|---|---|---|---|---|---|
| Magnesium Bisglycinate – Shifa | Amino-acid chelate | Does not rely on a carbonate acid-neutralisation reaction | High – greater systemic availability than oxide in comparative human data | 0.164 | Premium chelated magnesium with good bioavailability |
| Magnesium Malate – Shifa | Organic magnesium salt | Associated with malic acid; does not neutralise stomach acid like carbonate | High in comparative human data | 0.196 | Produced substantially greater serum Mg AUC than oxide |
| Magnesium Citrate – Shifa | Organic magnesium salt | Highly soluble and less dependent on gastric acidity than poorly soluble inorganic forms | High – strong comparative human evidence | Not measured in the same AUC study | Excellent solubility and human absorption evidence |
| Magnesium Oxide | Inorganic oxide | Poorly soluble; dissolution is strongly influenced by gastric acidity | Low compared with citrate and chelated forms | 0.109 | High elemental Mg content, but relatively poor bioavailability |
| Magnesium Carbonate | Inorganic carbonate | Requires gastric HCl for dissolution and neutralises acid during the process | More dependent on gastric conditions | No directly comparable AUC established | Consumes stomach acid and releases CO₂ during reaction |
In a randomized crossover study reviewed by EFSA, healthy volunteers received 150 mg elemental magnesium. Reported serum magnesium AUC values were 0.196 for di-magnesium malate, 0.164 for magnesium bisglycinate and 0.109 for magnesium oxide.
Compared with magnesium oxide in this study, serum magnesium AUC was approximately 50% higher with bisglycinate and 80% higher with di-magnesium malate.
These percentages describe the relative serum AUC observed in that particular study and should not be interpreted as the percentage of magnesium absorbed.
Magnesium Carbonate Requires Stomach Acid
Magnesium carbonate behaves differently from the three magnesium forms used in Shifa Triple Magnesium.
It reacts directly with hydrochloric acid (HCl) in the stomach:
MgCO₃ + 2HCl → MgCl₂ + H₂O + CO₂
This reaction is important for three reasons:
-
Magnesium carbonate requires gastric acid to dissolve.
-
It consumes and neutralises hydrochloric acid during dissolution.
-
The reaction releases carbon dioxide (CO₂).
This acid-neutralising property is also why magnesium carbonate is used in some antacid preparations.
Therefore, magnesium carbonate relies on an acidic gastric environment while simultaneously consuming some of the acid available in the stomach.
Why Gastric Acidity Becomes More Important With Age
The stomach normally maintains a strongly acidic environment. However, gastric acid secretion can decrease with increasing age, particularly in people with conditions such as atrophic gastritis.
When stomach acid decreases, gastric pH increases, meaning the stomach becomes less acidic.
This is particularly relevant for magnesium compounds that depend strongly on gastric acid for dissolution.
Increasing age → reduced gastric acid secretion → higher gastric pH → less favourable conditions for acid-dependent mineral dissolution
For magnesium carbonate, reduced stomach acidity can therefore make dissolution less favourable because carbonate requires hydrochloric acid to convert it into a soluble magnesium salt.
The issue may be even more relevant for people using acid-suppressing medicines such as proton-pump inhibitors (PPIs), which deliberately reduce gastric acid production.
Magnesium Citrate: Strong Evidence for Solubility
Magnesium citrate demonstrates why magnesium form matters.
In a study simulating gastric conditions ranging from virtually no gastric acid to peak acid secretion, magnesium citrate was substantially more soluble than magnesium oxide.
Magnesium citrate was approximately 55% soluble even without added acid.
By comparison, magnesium oxide was virtually insoluble in water and reached only approximately 43% dissolution even under simulated peak gastric acid secretion.
The same researchers subsequently demonstrated greater biological availability of magnesium citrate in human volunteers.
Following equivalent magnesium loads, the four-hour increase in urinary magnesium was:
Magnesium Citrate: 0.22 mg Mg/mg creatinine
Magnesium Oxide: 0.006 mg Mg/mg creatinine
These measurements demonstrate a substantially greater biological response to magnesium citrate, although urinary magnesium values should not be interpreted directly as percentage absorption.
Human Serum Data: Bisglycinate and Malate vs Oxide
Human comparative data also support the forms used in Shifa Triple Magnesium.
In a randomized crossover study reviewed by the European Food Safety Authority (EFSA), healthy adults received equivalent doses of elemental magnesium from different magnesium sources.
The reported serum magnesium AUC values were:
Di-Magnesium Malate: 0.196
Magnesium Bisglycinate: 0.164
Magnesium Oxide: 0.109
Therefore, compared with magnesium oxide, serum magnesium AUC was approximately:
80% higher with di-magnesium malate
50% higher with magnesium bisglycinate
This provides human evidence that the chemical form of magnesium can make an important difference to its systemic availability.
Why Shifa Uses Three Premium Magnesium Forms
Shifa Triple Magnesium combines:
Magnesium Bisglycinate
A premium amino-acid-chelated form with good human bioavailability and a strong reputation for gastrointestinal tolerance.
Magnesium Citrate
A highly soluble organic magnesium form supported by human studies demonstrating greater bioavailability than magnesium oxide.
Magnesium Malate
An organic magnesium form combining magnesium with malic acid. Human comparative data have demonstrated a substantially greater serum magnesium AUC than magnesium oxide.
Together, these provide:
3 PREMIUM MAGNESIUM FORMS
BISGLYCINATE • CITRATE • MALATE
300 mg ELEMENTAL MAGNESIUM PER SERVING
It's Sugar free, Keto friendly, as Sugar may deplete magnesium
NO MAGNESIUM OXIDE • NO MAGNESIUM CARBONATE
Rather than simply selecting a magnesium compound because it contains a high percentage of elemental magnesium by weight, Shifa Triple Magnesium combines three carefully selected forms with favourable solubility and bioavailability characteristics.
References
-
Lindberg JS, Zobitz MM, Poindexter JR, Pak CYC. Magnesium bioavailability from magnesium citrate and magnesium oxide. Journal of the American College of Nutrition. 1990;9(1):48–55.
-
Walker AF, Marakis G, Christie S, Byng M. Magnesium citrate found more bioavailable than other magnesium preparations in a randomised, double-blind study. Magnesium Research. 2003;16(3):183–191.
-
European Food Safety Authority (EFSA). Safety of magnesium malate as a novel food pursuant to Regulation (EC) No 258/97. EFSA Journal. 2018;16(6):5292.
-
U.S. National Institutes of Health, Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals.