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Calcium lactate

Calcium salt supplement (oral) · Mineral supplement

Also known as Cal-Lac

START
Elemental calcium 500 mg/day with food
TYPICAL MAX
Total intake ~2000–2500 mg elemental calcium/day
STOP IF
Hypercalcaemia, renal stones, or persistent constipation
WATCH
Serum/urinary calcium if high-dose; phosphate in CKD
CDSCO approvedOTCATC A12AA05
Dose laddermg/d
500low1kusual2kintake max
Renal dose adjustmenteGFR mL/min/1.73m²
FULLUsual supplementation if needed30CAUTIONCaution — CKD-MBD; specialist input90

KDIGO 2024 + manufacturer label

Pharmacokineticsplasma · t hours
1wONSET2wPEAK36s1dDURATION
ONSET
1w · repletion
PEAK
2w · store effect
36s · homeostatic
DURATION
1d · daily dosing
EXCRETION
Renal and faecal — homeostatic
route + CYP
INTERACTIONS
2 major
SEVERE in our sources
PREGNANCY
Safe at recommended intakes.
FDA category + note
Top interactionssee all 6
  • BictegravirSevereDatabaseDDInter
  • DolutegravirSevereDatabaseDDInter

Mechanism

Provides elemental calcium (~13% by weight) for bone mineralisation and to correct/prevent calcium deficiency states; lactate moiety is metabolised.

Indications

Dietary calcium supplementationMild–moderate hypocalcaemia (oral)Adjunct in osteoporosis/osteomalacia

Dosing

Adult
Elemental calcium 500–1000 mg/day in divided doses with meals.
Pediatric
Per age-specific calcium requirement.
Renal adjustment
Caution in CKD-MBD; specialist guidance for replacement.
Hepatic adjustment
No adjustment.
Geriatric
Common osteoporosis component; avoid excess.
Max dose
Total elemental calcium intake ~2000–2500 mg/day (all sources)

Pharmacokinetics

Onset
Repletion over weeks
Peak effect
Serum calcium tightly regulated
Duration
Dosing-dependent
Half-life
Not applicable (physiologic homeostasis)
Bioavailability
~25–30% (vitamin D / pH dependent)
Protein binding
~40% (serum albumin-bound calcium)
Metabolism
Lactate metabolised; calcium not metabolised
Excretion
Renal and faecal — homeostatically regulated

Contraindications

  • Hypercalcaemia
  • Severe hypercalciuria / calcium-stone disease
  • Renal calculi (calcium-containing)
  • Hypersensitivity

Side effects

Common
ConstipationBloatingNauseaMild dyspepsia
Serious
  • Hypercalcaemia (excess intake)
  • Renal calculi (chronic excess)
  • Milk-alkali syndrome (excess with alkali)

Pregnancy & lactation

Pregnancy

Safe at recommended intakes.

Lactation

Compatible at recommended intakes.

Drug interactions

Bictegravir
Severe
Database

Clinical effect not specified

Source: DDInter

Dolutegravir
Severe
Database

Clinical effect not specified

Source: DDInter

Digoxin
Moderate
Database

Hypercalcaemia potentiates digoxin

Avoid hypercalcaemia; monitor

Source: Kimi deep-research + Cla

Levothyroxine
Moderate
Database

Reduced absorption

Separate dosing widely

Source: Kimi deep-research + Cla

Tetracyclines
Moderate
Database

Calcium chelation

Separate by ≥2–4 h

Source: Kimi deep-research + Cla

Thiazide Diuretics
Moderate
Database

Reduced calcium excretion

Monitor serum calcium

Source: Kimi deep-research + Cla

6 additional low-confidence interactions hidden — those rows lack a documented mechanism or management plan in our sources.

Related guidelines

Ask House about Calcium lactate

Continue into a citation-backed clinical answer with the drug context already attached.

Sources: KD Tripathi 7e, Katzung, BNF, Harriet Lane·Verified: 2026-05-20 · House clinical team·Cockpit curated: 2026-05-20