Calcium
Also known as Calcium citrate, Calcium carbonate
Calcium is the most abundant mineral in the body and the main building block of bone. It is best obtained from food, but supplements help those who fall short — ideally alongside vitamin D3 and K2 to ensure it ends up in bone.
Benefits
Maintains bone density
ModerateAdequate calcium with vitamin D supports bone strength and lowers fracture risk.
Pros & cons
Pros
- Essential for bone health
- Inexpensive
Cons
- Best paired with D3 and K2
- Can inhibit iron and magnesium absorption
Side effects
Constipation and bloating
Carbonate forms in particular can cause GI discomfort.
Arterial concerns if unbalanced
High supplemental calcium without K2 may contribute to soft-tissue calcification.
How to take it
Typical dose
500–1,000 mg per day from supplements, only to fill dietary gaps
Timing
Citrate any time; carbonate with food. Split doses above 500 mg.
Common forms
Tip: Prioritize dietary calcium; pair supplements with D3 and K2.
What the research says
Calcium, vitamin D, and fractures
ModerateCombined calcium and vitamin D reduces fracture risk, especially in institutionalized older adults.
How it connects
Relationships between Calcium and other supplements in the matrix.
Vitamin D3 is required to absorb dietary and supplemental calcium.
Compare the pairingCalcium competes with iron for absorption — separate the two by a couple of hours.
Compare the pairingVery large single doses can compete for absorption; keep the two balanced.
Compare the pairing