Calcium Citrate
Calcium Citrate is a supplemental form of calcium used to prevent or treat calcium deficiency in individuals who cannot get adequate calcium from their diet. It is commonly prescribed for conditions affecting bone health, such as osteoporosis and osteomalacia, and is also used to support normal bone development during pregnancy, breastfeeding, and aging.
A mineral supplement that provides calcium to support bone health and treat or prevent calcium deficiency.
This medication carries a boxed (black box) warning — the strongest type of FDA warning. Review the full prescribing information before use.
Key facts at a glance
- ATC
- A12AA13
- RxNorm
- 47613
- Generic
- Calcium Citrate
- Class
- atc-a12
- Brands
- Calcet
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- tablet, powder, capsule
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 500mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 250mg twice daily
- Maximum
- consult physician
- Frequency
- every 12 hours
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 400mg daily
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
10 groupspregnancy
first trimesteruse as directed, do not exceed recommended dose
do not exceed 2500mg daily elemental calcium from all sources
monitor calcium levels if high-dose supplementation required
Use with caution and monitor for adverse effects.
pregnancy
second trimesteruse as directed, do not exceed recommended dose
maintain adequate calcium intake of 1000-1300mg daily
routine prenatal calcium monitoring
Use with caution and monitor for adverse effects.
pregnancy
third trimesteruse as directed, do not exceed recommended dose
ensure adequate calcium intake for fetal bone mineralization
routine prenatal monitoring
Use with caution and monitor for adverse effects.
lactation
breastfeedingno adjustment needed
continue calcium supplementation as needed to meet daily requirements of 1000-1300mg
none routinely required
pediatric_age
children 1 3 yearsage-appropriate dosing only
use pediatric formulations, recommended daily intake 700mg
monitor as per pediatric guidelines
Use with caution and monitor for adverse effects.
pediatric_age
adolescentsage-appropriate dosing
adolescents need 1300mg calcium daily for bone growth
routine pediatric monitoring
Use with caution and monitor for adverse effects.
geriatric
elderly over 65may require supplementation due to decreased absorption
assess calcium and vitamin D status, consider supplementation if dietary intake inadequate
periodic calcium and vitamin D level monitoring
Use with caution and monitor for adverse effects.
renal_impairment
mild renal impairmentuse with caution, monitor calcium levels
monitor serum calcium and phosphorus regularly
regular serum calcium, phosphorus, and creatinine monitoring
Use with caution and monitor for adverse effects.
renal_impairment
severe renal impairmentavoid or use only under close supervision
contraindicated in patients with hypercalcemia, use cautiously in end-stage renal disease
frequent monitoring of calcium, phosphorus, and calcium-phosphorus product
Use of this medication in this population requires careful consideration of risks and benefits.
hepatic_impairment
mild to moderateno adjustment typically required
no special precautions for mild to moderate hepatic impairment
none routinely required
Statistics and clinical data
Commonly prescribed since
General prescribing information for calcium supplements
Drug class
Classification as mineral supplement
Common uses
Common therapeutic uses
Absorption
Absorption characteristics compared to calcium carbonate
Treatment and prevention of calcium deficiency; support for bone health in osteoporosis, osteomalacia, and hypoparathyroidism; supplementation during pregnancy, breastfeeding, and in older adults who may have increased calcium needs.
Provides bioavailable elemental calcium, an essential mineral required for bone and tooth formation, muscle contraction, nerve signal transmission, and blood coagulation. Calcium citrate is absorbed with or without food, making it suitable for individuals with reduced stomach acid.
Should be taken as directed; adequate vitamin D levels support calcium absorption. Calcium can interact with certain medications including bisphosphonates, antibiotics, and some heart medications. Side effects may include constipation, gas, or bloating. Those with hypercalcemia, kidney stones, or certain kidney disorders should consult a healthcare provider before use.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 24, 2026. · Read our editorial policy