Key Takeaways
What Does a Calcium Magnesium Supplement Actually Do?
Calcium and magnesium have different but complementary roles throughout the body. A supplement may be useful when normal dietary intake does not consistently provide enough of either mineral.
Supports Bones & Teeth
Almost all calcium in the body is stored in bones and teeth. Around 50–60% of magnesium in the adult body is also found in bone.
Supports Muscle Function
Calcium contributes to muscle contraction, while magnesium participates in muscle activity, nerve impulses and electrolyte balance.
Supports the Nervous System
Calcium helps nerves transmit messages, while magnesium is necessary for normal nerve function and participates in hundreds of biochemical reactions.
How Much Calcium and Magnesium Do Adults Need?
These totals include nutrients obtained from food as well as supplements. If your diet already provides plenty of calcium and magnesium, adding a large supplement may provide more than you need.
Food Sources Should Come First
Calcium-Rich Foods
- Milk
- Yogurt
- Fortified soy milk
- Calcium-set tofu
- Fish with edible bones
Magnesium-Rich Foods
- Pumpkin seeds
- Almonds
- Spinach
- Beans
- Whole grains
- Soy foods
What Should You Check Before Buying a Calcium Magnesium Supplement?
Elemental Amount
Check the actual elemental calcium and magnesium per serving.
Mineral Form
Look beyond the mineral name and check the specific compound used.
Serving Size
Check how many tablets are needed for the stated amount.
Nutrient Overlap
Check your multivitamin and other supplements for the same minerals.
Calcium and Magnesium Forms Compared
| Mineral Form | What to Know |
|---|---|
| Calcium Carbonate | Generally better taken with food. |
| Calcium Citrate | Less dependent on stomach acid. |
| Magnesium Citrate, Chloride, Lactate & Aspartate | NIH reports these forms tend to be more bioavailable than some alternatives. |
| Magnesium Oxide & Sulfate | Generally reported as less bioavailable than several other common forms. |
Can You Take Too Much Calcium or Magnesium?
Yes. More calcium or magnesium is not automatically better, and supplement intake should be considered alongside food and any other products you use.
Calcium
The adult tolerable upper intake level generally ranges from 2,000–2,500 mg per day, depending on age. Supplemental calcium can also interact with certain medications.
Magnesium
The adult upper limit of 350 mg per day applies specifically to magnesium from supplements and medications, not magnesium naturally present in food.
“The goal of a mineral supplement is to fill a nutritional gap, not to push intake as high as possible.”
Where Can a Combination Supplement Fit?
For someone who has identified a reason to supplement, a combination formula can be more convenient than taking several individual tablets.
QNT Calcium-Magnesium-Zinc
QNT Calcium-Magnesium-Zinc currently lists 500 mg calcium and 250 mg magnesium per tablet, along with zinc, manganese and iodine.
QNT recommends taking one tablet per day with a meal and states that the supplement should complement rather than replace a varied diet.
View QNT Calcium-Magnesium-ZincFrequently Asked Questions
Is it good to take calcium and magnesium every day?
It can be appropriate when your diet does not provide enough or when a healthcare professional recommends supplementation. However, not everyone needs a daily calcium magnesium supplement. Check your total intake from food, fortified products and other supplements.
What are the 7 signs your body needs magnesium?
Possible signs associated with magnesium deficiency include:
These symptoms are not specific to magnesium deficiency and should not be used to self-diagnose. Severe deficiency can also cause seizures and other serious symptoms.
What are the benefits of taking calcium and magnesium?
The main nutritional benefits are supporting adequate intake of minerals required for bones, teeth, normal muscle function and nerve function. Magnesium also participates in energy production and numerous enzyme systems, while calcium contributes to blood clotting, hormonal secretion and muscle contraction.
What organ is most affected by magnesium?
There is no single organ that magnesium affects most because it is involved throughout the body. However, the kidneys are central to magnesium regulation because they control how much magnesium is retained or excreted.
Severe magnesium deficiency can affect the nervous system, muscles and heart rhythm, while kidney impairment can increase the risk of magnesium toxicity.
The Bottom Line
A calcium magnesium supplement is primarily useful for helping fill dietary gaps in two minerals required for normal bones, muscles and nerve function.
That does not make supplementation necessary for everyone. Start by looking at how much calcium and magnesium you receive from dairy or fortified alternatives, vegetables, legumes, nuts, seeds and other foods.
If you choose a supplement, compare elemental amounts, mineral forms, serving size and nutrient overlap rather than simply choosing the product with the largest numbers.
Sources & References
- NIH Office of Dietary Supplements — Calcium Health Professional Fact Sheet
- NIH Office of Dietary Supplements — Magnesium Health Professional Fact Sheet
- QNT Sport — Calcium-Magnesium-Zinc product information
