Clinically formulated cellular electrolyte complex. Reviewed for biochemical accuracy, mineral bioavailability, and dietary compliance.
Source Naturals K-Mag-C™ is an advanced, bioavailable electrolyte and antioxidant complex engineered to restore essential intracellular mineral balance. Combining potassium, magnesium, and non-acidic buffered vitamin C, this physician-inspired formula directly addresses the widespread micronutrient gaps created by modern, high-sodium diets and metabolic stress.
Unlike conventional single-mineral formulas or basic potassium chloride supplements, K-Mag-C utilizes organic mineral carriers - including magnesium malate and potassium citrate—alongside mineral ascorbates. This synergistic matrix supports intracellular electrolyte homeostasis, normal cardiac rhythm, skeletal muscle contraction, and cellular ATP energy generation.
The Science of K-Mag-C: Synergistic Cellular Mechanisms
Intracellular minerals do not function in isolation. The biological efficacy of K-Mag-C relies on the direct physiological interplay between potassium, magnesium, and ascorbic acid:
1. The Potassium-Magnesium Interdependence (Na+/K+-ATPase Pump)
Potassium ($K+) is the primary intracellular cation, while sodium ($Na+) dominates extracellular fluid. This gradient is governed by the magnesium-dependent enzyme Sodium-Potassium Adenosine Triphosphatase (Na+/K+-ATPase). Clinical research confirms that magnesium deficiency impairs this pump, leading to renal potassium wasting through renal outer medullary potassium (ROMK) channels. Supplementing potassium without adequate magnesium is clinically inefficient; K-Mag-C provides both minerals simultaneously to restore true intracellular equilibrium (Whang et al., Arch Intern Med, 1992).
2. Krebs Cycle Intermediates & Mitochondrial Energy
Rather than utilizing poorly absorbed, low-cost inorganic salts like magnesium oxide, K-Mag-C provides magnesium partially chelated as magnesium malate. Malic acid is a critical intermediate in the Krebs (citric acid) cycle, facilitating the conversion of carbohydrates and fats into adenosine triphosphate (ATP). This makes K-Mag-C an ideal formulation for individuals experiencing cellular fatigue, muscle soreness, or high physical exertion.
3. Buffered, Non-Acidic Vitamin C Delivery
Each serving delivers 1,000 mg of Vitamin C bound to potassium and magnesium (mineral ascorbates). Unlike unbuffered, synthetic ascorbic acid, which can trigger gastric distress and acid reflux at therapeutic doses, buffered ascorbates are gentle on the digestive tract while providing sustained antioxidant cellular protection against reactive oxygen species (ROS).
4. Cardiovascular Rhythm & Neuromuscular Health
Potassium and magnesium work in tandem to regulate cardiac myocyte action potentials and endothelial smooth muscle relaxation. Dietary magnesium acts as a physiological calcium antagonist, preventing arterial vasospasms and muscle cramping, while potassium facilitates normal arterial vasodilation and balanced blood pressure regulation already within normal ranges.
Why K-Mag-C Outperforms Standard Electrolyte Supplements
Formula Characteristic
Source Naturals K-Mag-C™
Standard Potassium / Magnesium Salts
Mineral Carriers
Bioavailable Citrates, Malates & Ascorbates
Inorganic Oxides, Chlorides, or Carbonates
Cellular Absorption Rate
High intracellular uptake via organic transport ligands
Low bioavailability; high rate of unabsorbed excretion
Gastrointestinal Tolerance
Gentle; fully buffered, non-acidic ascorbates
Commonly causes osmotic diarrhea or acid stomach upset
Synergistic Co-Factors
Triple-action: Potassium + Magnesium + Vitamin C
Isolated single nutrients lacking cofactor transport
Complete Ingredients & Supplement Facts
Supplement Facts
Serving Size: 2 Tablets
Servings Per Container: 60
Amount Per Serving
% Daily Value
Vitamin C (as magnesium & potassium ascorbates)
1,000 mg (1,111% DV)
Magnesium (as magnesium malate & ascorbate)
150 mg (36% DV)
Potassium (as potassium citrate & ascorbate)
198 mg (4% DV)
* Percent Daily Values (% DV) are based on a 2,000 calorie diet.
Other Ingredients: Stearic acid, dibasic calcium phosphate, modified cellulose gum, colloidal silicon dioxide, and magnesium stearate.
Dietary & Allergen Information: Suitable for vegetarians. Contains NO yeast, dairy, egg, gluten, soy, or wheat. Free of sugar, starch, preservatives, and artificial colors, flavors, or fragrances.
Suggested Use & Clinical Safety Considerations
Directions: Take 1 to 2 tablets twice daily with meals, or as recommended by your qualified healthcare practitioner. Adequate water intake is recommended during electrolyte repletion.
Scientific & Clinical References
Whang, R., et al. (1992). Magnesium depletion as a cause of refractory potassium repletion. Archives of Internal Medicine, 152(1), 40–45.
National Institutes of Health (NIH) Office of Dietary Supplements. Potassium & Magnesium Fact Sheets for Health Professionals.
Carr, A. C., & Frei, B. (1999). Toward a new recommended dietary allowance for vitamin C based on antioxidant and health effects in humans. The American Journal of Clinical Nutrition, 69(6), 1086–1107.
Houston, M. C. (2011). The importance of potassium in managing hypertension. Current Hypertension Reports, 13(4), 309–317.
Frequently Asked Questions About Source Naturals K-Mag-C
Why are potassium and magnesium combined in Source Naturals K-Mag-C?
Potassium and magnesium have a biological codependence inside human cells. The Sodium-Potassium ATPase pump requires magnesium to actively transport potassium across cellular membranes. When magnesium levels are low, cells struggle to retain potassium, rendering single-mineral potassium supplements significantly less effective. K-Mag-C combines both to optimize absorption and cellular retention.
What makes the Vitamin C in this formula "buffered"?
Standard Vitamin C is formulated as pure ascorbic acid, which has an acidic pH and can cause stomach irritation, hyperacidity, or digestive upset at doses of 1,000 mg. In K-Mag-C, Vitamin C is bound to minerals (potassium ascorbate and magnesium ascorbate). This neutralizes the acidity into a non-acidic, stomach-friendly form that is absorbed smoothly without gastric irritation.
Why does K-Mag-C contain 198 mg of potassium per serving?
FDA regulations generally restrict over-the-counter potassium supplements to no more than 99 mg of elemental potassium per single tablet to protect gastrointestinal lining from concentrated potassium exposure. K-Mag-C delivers 198 mg per two-tablet serving (99 mg per tablet) in gentle citrate and ascorbate forms, safely complementing dietary potassium intake.
Can I take K-Mag-C if I am on blood pressure medications?
If you are taking blood pressure medications - specifically ACE inhibitors (such as lisinopril), ARBs (such as losartan), or potassium-sparing diuretics (such as spironolactone)—you must consult your physician prior to taking any potassium supplement. These medications can elevate blood potassium levels, making supplemental potassium intake unsuitable without professional oversight.
Does K-Mag-C contain common allergens or artificial additives?
No. Source Naturals K-Mag-C (SN0787) is suitable for vegetarians and formulated without yeast, dairy, egg, gluten, soy, or wheat. It contains no sugar, preservatives, artificial colors, artificial flavors, or fragrances.
