What 'macro' means
Minerals are grouped by how much the body needs. MedlinePlus explains that 'you need larger amounts of macrominerals,' which 'include calcium, phosphorus, magnesium, sodium, potassium, chloride and sulfur' [1]. (The complementary group is the trace minerals, needed in small amounts.)
What the macrominerals do
- Calcium and phosphorus build and maintain bones and teeth — see [getting calcium from food](/learn/getting-calcium-from-food) and [phosphorus](/learn/phosphorus-intake-and-balance).
- Magnesium supports hundreds of enzyme reactions, nerves, and muscles — see [magnesium deficiency risk](/learn/magnesium-deficiency-risk).
- Sodium, potassium, and chloride are electrolytes that balance fluids and support nerve and muscle signaling — see [electrolytes and hydration](/learn/electrolytes-and-hydration).
- Sulfur is part of certain amino acids and proteins.
Which gaps are common
Unlike most trace minerals, a few macrominerals are genuinely under-consumed in typical Western diets:
- Calcium and magnesium intakes fall short for many people.
- Potassium intake is often low, while sodium is often high — the opposite of the recommended balance.
This is why calcium, magnesium, and potassium are among the more commonly considered supplements, while sodium and chloride almost never need supplementing.
Food first, then targeted supplements
A balanced diet — dairy or fortified alternatives, leafy greens, legumes, nuts, whole grains, fruit, and vegetables — supplies macrominerals well [1]. Where intake is low, a targeted supplement (for example, magnesium or calcium) can help, but more isn't better: potassium and magnesium can build up in people with reduced kidney function, and high calcium has its own limits.
Practical guidance
- Prioritize food sources; reserve supplements for identified gaps.
- Don't megadose — macrominerals have upper limits too.
- If you have kidney concerns, review potassium, magnesium, and phosphorus with your care team.