P1

Calcium is an essential nutrient that is found in dairy products, such as milk and cheese. It has been used to lower blood pressure, promote weight loss, and improve bone strength. Calcium can be taken as a pill or powder.

Dosages

500 milligrams 1 to 2 times daily.

P5

Likely effective

  • Colorectal adenomas—likely to reduce occurrence and promote healing E1, E2
  • Hypercalcemia after thyroidectomy—likely to prevent hypercalcemia after surgery I1, I2
  • Hyperlipidemia—likely to help control cholesterol and blood fat levels G1
  • Osteoporosis—likely to prevent fracture and promote bone health when taken with vitamin D K1
  • Preeclampsia—likely to reduce risk L1-L5
  • Weight loss—likely to reduce body weight in people with normal BMI O1

May be effective

  • Blood pressure—may lower blood pressure in people with normal blood pressure A1
  • Bone mineral density—may have small increases in bone mineral density that is unlikely to lead to a reduction in fracture risk B1, B2
  • Fall prevention—may prevent falls in older adults, especially when used with vitamin D F1-F3
  • Premenstrual syndrome (PMS)—may reduce symptoms M1, M2

May not be effective

  • Cognitive function—may not ease symptoms D1

Unlikely to be effective

  • Cardiovascular events—increases the risk of cardiovascular events and heart attack C1, C2
  • Stroke—increases the risk of stroke N1

Not enough data to assess

  • Hypertensive disorders of pregnancyH1
  • ObesityJ1

Editorial process and description of evidence categories can be found at EBSCO NAT Editorial Process.

P6

It is likely safe to take calcium in small doses for a short time. High doses of calcium may not be safe. Not enough studies have been done to say whether it is safe to take for a long period

Interactions

Talk to your doctor about any supplements or therapy you would like to use. Some can interfere with treatment or make conditions worse such as:

  • People with heart problems should talk to their doctors before taking calcium. It may worsen symptoms.