NOW® CAL-MAG CITRATE POWDER with Vitamin D3 (8 oz / 227 g)
Highly Absorbable 1:1 Bone, Nerve, and Muscle Support in an Unflavored, Zero-Filler Drink Mix
If you struggle to swallow bulky mineral tablets or experience poor digestion from basic drugstore calcium, NOW CAL-MAG CITRATE POWDER delivers elemental nutrition your body can readily absorb. By binding calcium and magnesium to natural citric acid, this fully reacted mineral powder dissolves easily in cold liquid and bypasses common digestive roadblocks. Fortified with Vitamin D3, it provides the essential nutritional framework for bone density, nighttime muscle comfort, and nervous system relaxation.
Key Advantages at a Glance:
✓Equal 1:1 Mineral Balance: 400 mg Calcium and 400 mg Magnesium per serving to keep muscles and nerves working smoothly together.
✓Superior Bioavailability: Pre-reacted citrate forms absorb efficiently even in adults with low stomach acid.
✓Fortified with Vitamin D3: 200 IU (5 mcg) of cholecalciferol to aid intestinal calcium transport into skeletal bone.
✓Zero Excipients or Fillers: 100% pure mineral powder with no magnesium stearate, artificial sweeteners, sugars, or binders.
✓Rigorous Purity Testing: Screened in ISO/IEC 17025 accredited laboratories to ensure heavy metal levels remain far below strict regulatory limits.
The Bioavailability Advantage: Why Citrate Outperforms Carbonate and Oxide
Not all mineral supplements perform the same way in your digestive tract. Mass-market formulas often rely on calcium carbonate (ground limestone/chalk) and magnesium oxide (calcined mineral salt). While these ingredients provide dense elemental weight on a label, their biological utility is constrained by basic human physiology:
The Stomach Acid Constraint: Calcium carbonate requires a high concentration of hydrochloric stomach acid to break its chemical bonds and liberate free calcium ions. Stomach acid production declines steadily with age, and millions of adults take acid blockers or proton pump inhibitors (PPIs). Under low-acid conditions, carbonate salts pass through poorly absorbed, frequently triggering constipation and bloating.
Pre-Ionized Citrate Absorption: Calcium citrate is an organic salt pre-bound to citric acid. Clinical research demonstrates that calcium citrate dissolves independently of gastric pH, allowing healthy intestinal uptake with or without meals. In comparative trials, calcium citrate demonstrated 22% to 27% greater bioavailability than calcium carbonate (Sakhaee et al., American Journal of Therapeutics, 1999; Harvey et al., Journal of Bone and Mineral Research, 1988).
Magnesium Citrate for Gentle Cellular Delivery: Magnesium oxide exhibits clinical absorption rates as low as 4%, drawing excessive water into the lower bowel and causing laxative flushing before tissue saturation occurs. Fully reacted magnesium citrate provides significantly higher bioavailability and systemic cellular retention (Walker et al., Magnesium Research, 2003; Lindberg et al., Journal of the American College of Nutrition, 1990).
Urinary Tract Safety: Citrate ions excreted into urine bind with free urinary calcium, helping inhibit the crystallization of calcium oxalate stones.
The 1:1 Ratio: Balancing Neuromuscular Contraction and Relaxation
Standard nutritional guidelines historically promoted an uncalibrated 2:1 ratio favoring calcium. Modern research shows that high calcium intake unaccompanied by proportional magnesium can cause neuromuscular irritability and mineral imbalance (Rosanoff et al., Advances in Nutrition, 2016).
Calcium and magnesium function as coordinated physiological partners:
Calcium Stimulates Contraction: Calcium floods muscle fibers to initiate mechanical contraction and propagate nerve signals. Without adequate counter-regulation, excess calcium keeps fibers in a state of continuous tension.
Magnesium Governs Relaxation: Magnesium serves as the physiological gatekeeper, pumping calcium out of cells so muscle fibers can relax, recover, and avoid nighttime cramps. It also modulates GABA neurotransmitters to support nervous system calm.
Cardiovascular Protection: Magnesium acts as an endogenous calcium channel regulator, keeping calcium dissolved in circulation and directing it toward skeletal bone rather than soft arterial tissue.
Vitamin D3 Activation: Enzymes responsible for converting inactive Vitamin D into circulating calcitriol require magnesium as an obligate cofactor. Providing equal 400 mg ratios ensures all metabolic pathways work synchronously.
NOW Foods Quality Standards: Rigorous Contaminant Limits and Lab Protocols
Because raw minerals are extracted from natural geological sources, unrefined lots carry the risk of heavy metal contamination. NOW maintains rigorous quality control infrastructure to eliminate these risks:
Testing Protocol
Consumer Safety Benefit
ISO/IEC 17025:2017 Accreditation
NOW's in-house analytical testing laboratories are independently accredited by the American Association for Laboratory Accreditation (A2LA), validating precise instrument calibration and testing competence.
ICP-MS Heavy Metal Screening
Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), raw powders are screened down to parts per billion (ppb) for lead, arsenic, cadmium, and mercury to ensure compliance with USP and California Proposition 65 limits.
FTIR Chelation Verification
Fourier-Transform Infrared Spectroscopy confirms true molecular chelation, ensuring raw ingredients are fully reacted citrates rather than cheap mineral blends diluted with unreacted oxides.
31,000+ Monthly Quality Tests
NOW conducts tens of thousands of individual tests monthly across raw materials and finished products, receiving national recognition for uncovering counterfeit and sub-potent products sold across third-party marketplaces.
Verified against official NOW Foods product specifications for Item Code 1243 (SKU N1243):
Supplement Facts
Serving Size: 1 1/2 Level Teaspoons (approx. 5 g)
Servings Per Container: about 45
Amount Per Serving
% Daily Value
Vitamin D3 (as Cholecalciferol) 5 mcg (200 IU)
25%
Calcium (from Calcium Citrate) 400 mg
31%
Magnesium (from Magnesium Citrate) 400 mg
95%
Other Ingredients: None.
The Calcium Citrate and Magnesium Citrate are fully reacted mineral supplements.
Allergen Profile: Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish, or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens. Certified Kosher, Non-GMO Project Verified, Halal, Keto-Friendly, and Vegan/Vegetarian.
Usage Guidelines & Exothermic Reaction Advisory
Important Handling Notice: Dissolve in Cold Liquid Only
Pure, unadulterated calcium and magnesium citrate powders produce natural thermal energy upon hydration (known as an exothermic reaction). When the dry powder first contacts liquid, it creates a brief temperature increase.
Never place dry powder directly in the mouth and do not mix with hot liquids. The serving must be completely stirred into at least 8 ounces of cold liquid before drinking.
Preparation Steps:
Measure 8 to 10 ounces of cold water, cold electrolyte beverage, or chilled juice into a glass.
Add 1 1/2 level teaspoons of powder.
Stir briskly with a spoon or whisk until the powder is fully dissolved.
Consume once daily with food, or in the evening approximately 45 minutes prior to sleep.
Storage: Store in a cool, dry place after opening. Product is filled by weight, not volume. Settling of powder naturally occurs during shipping.
Why Order From VitaNet®, LLC?
Purchasing vitamins directly from an authorized, established source protects you from unauthorized marketplace distributors, counterfeit lots, and expired inventory.
VitaNet®, LLC is an independent, family-owned discount retailer based in Hartville, Ohio[cite: 1].
VitaNet®, LLC has served customers online since 1995 with over 31 years of direct industry experience[cite: 1].
Maintains an A+ rating with the Better Business Bureau[cite: 1].
Carries a curated catalog of over 16,000 name-brand vitamins and supplements stored in climate-controlled facilities[cite: 1].
Backed by an unconditional 100% money-back guarantee that covers return shipping costs even on opened products[cite: 1].
Frequently Asked Questions
What does NOW CAL-MAG CITRATE POWDER taste like?
Because it contains zero sugar, flavorings, or sweeteners, the powder has a mild, clean, slightly tart mineral flavor natural to citric acid. It blends easily into cold water, lemon water, or fruit smoothies.
Can I take this supplement if I have low stomach acid or use acid blockers?
Yes. Unlike calcium carbonate, calcium citrate does not rely on stomach acid to dissolve. Clinical evaluations confirm that individuals with hypochlorhydria or those using proton pump inhibitors absorb calcium citrate significantly better than carbonate forms.
Will this powder trigger constipation or loose stools?
Standard calcium pills often induce constipation, while pure magnesium oxide can act as a harsh laxative. By balancing elemental calcium and magnesium in an equal 1:1 citrate ratio, the digestive tendencies counterbalance each other. If stools soften, adjust the serving to 1 teaspoon and gradually increase.
Why does the formula include Vitamin D3?
Vitamin D3 stimulates intestinal synthesis of calcium-transport proteins, enabling elemental calcium to enter systemic circulation. Magnesium then works alongside Vitamin D3 to direct calcium deposition into the bone matrix.
When is the best time of day to take this powder?
While it can be taken anytime with food, many users prefer taking it 45 to 60 minutes before bedtime. Magnesium helps soothe muscle fibers and settle the central nervous system, supporting restful sleep and easing nighttime leg tension.
How does NOW test this product for lead and heavy metals?
NOW tests every incoming production lot using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) inside ISO/IEC 17025 accredited analytical laboratories. This technique detects trace contaminants at parts-per-billion levels to confirm compliance with USP standards and California Proposition 65 limits.
