Calcium carbonate: Mild hypocalcemia – dosing, side effects, evidence A – Evigrade
Calcium carbonate
Mineral supplements. Calcium
Código ATC: A12AA04(Calcium carbonate)
Marcas comerciales
Tums, Caltrate, Os-Cal, Rolaids
Mecanismo de acción
A source of elemental calcium, providing 40% by mass. In the stomach it dissociates into calcium and bicarbonate ions. Calcium is absorbed in the small intestine by active vitamin D-dependent transport and passive diffusion. Bicarbonate neutralizes hydrochloric acid – hence the antacid effect. Bioavailability depends on gastric acidity: hypoacidity or PPI therapy reduces absorption, in which case organic calcium salts (citrate) are preferred.
Indicaciones
A
Mild hypocalcemia
Primera línea
In mild asymptomatic hypocalcemia (total calcium 2.0–2.2 mmol/L), oral calcium at 1000–1500 mg elemental calcium daily plus vitamin D usually normalizes the level. Calcium is rechecked at 1–2 weeks. If hypocalcemia persists, magnesium, PTH, vitamin D and eGFR are evaluated.
Calcium carbonate combined with vitamin D is a mandatory background component of postmenopausal osteoporosis therapy. The standard dose is 1000–1200 mg elemental calcium daily plus 800–1000 IU vitamin D3. Dietary calcium intake is considered, and the dose is adjusted so total intake does not exceed 1500 mg/day. Calcium monotherapy without disease-modifying therapy (bisphosphonates, denosumab, romosozumab) does not prevent fractures in confirmed osteoporosis.
For occasional heartburn and acid regurgitation, calcium carbonate as an antacid rapidly neutralizes acid and relieves symptoms. The effect is short-lived (30–60 minutes). Symptoms more than twice a week require workup (GERD, H. pylori, functional dyspepsia) and consideration of a PPI. Antacid use beyond 2 weeks without effect is reassessed.
Calcium supplementation alone, without vitamin D and disease-modifying therapy, does not reduce fracture risk in most patients with confirmed osteoporosis. International guidelines treat calcium only as a background component combined with vitamin D and mandatory disease-modifying therapy (bisphosphonates, denosumab, romosozumab). «Calcium for bones» without full assessment and disease-modifying therapy is marketing positioning.
Calcium supplementation for primary cardiovascular prevention is not indicated. The 2018 concluded that in asymptomatic postmenopausal women, additional calcium and vitamin D supplementation provides no advantage over a balanced diet for fracture and CVD prevention. The 2010–2013 meta-analyses (Bolland et al.) suggested a possible increase in MI risk with isolated calcium, although subsequent larger analyses have not confirmed the effect.
Taken with or right after meals for optimal absorption – gastric acidity increases bioavailability. Daily dose is split into 2–3 doses (maximum 500 mg elemental calcium is absorbed per dose; the rest is not used). Co-administration with milk drinks is not required and does not improve bioavailability.
Monitorización
With long-term use (over 6 months), monitor serum calcium, phosphorus, creatinine and 24-hour urinary calcium every 6 months. With hypercalciuria (over 7.5 mmol/day), the dose is reduced or the drug withdrawn.
Situaciones especiales
Maintain at least 2 hours between calcium carbonate and levothyroxine, fluoroquinolones, tetracyclines and bisphosphonates – calcium carbonate reduces their absorption. On PPIs or H2 blockers, calcium carbonate bioavailability is reduced – patients on long-term acid suppression should use calcium citrate or other organic salts. In oxalate stone disease, the dose is individualized and kept within the physiological range.
Mitos frecuentes
Myth: «more calcium means stronger bones». Fact: beyond 1500 mg daily, additional calcium offers no extra benefit and increases hypercalciuria and stone disease risk.
Myth: «every woman over 40 needs calcium for osteoporosis prevention». Fact: the 2018 found no benefit of prophylactic supplementation in asymptomatic women. Adequate dietary intake is usually enough; supplements are indication-based after risk assessment.
Myth: «calcium and vitamin D alone treat osteoporosis». Fact: confirmed osteoporosis requires disease-modifying therapy (bisphosphonates, denosumab, romosozumab). Calcium and vitamin D are background components.
Interacciones con nutrientes
Iron
Calcium competes with iron for absorption in the duodenum. In patients with iron-deficiency anemia, a 2-hour interval between calcium and iron supplements is maintained.
Levothyroxine
Calcium carbonate forms insoluble complexes with levothyroxine in the gut lumen and reduces its absorption. With concurrent dosing, the levothyroxine dose becomes insufficient, leading to hypothyroidism. A separation of at least 4 hours is maintained between fasting morning levothyroxine and calcium carbonate.
Fluoroquinolones
Calcium chelates with fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin) and reduces their absorption by 30–50%. A separation of at least 2 hours before and 6 hours after a fluoroquinolone dose is maintained before calcium carbonate.
Bisphosphonates
Calcium chelates oral bisphosphonates (alendronate, risedronate, ibandronate) and blocks their absorption completely. Bisphosphonates are taken strictly fasting 30–60 minutes before breakfast, no later than the first meal and no earlier than 30 minutes before calcium. Failure to observe the interval nullifies antiresorptive therapy.
Interacciones farmacológicas
1 par encontrado. Ordenadas de críticas a menores.
Resumen breve de la ficha técnica oficial. No sustituye el texto completo ni la consulta médica. Ficha del 26/05/2022. Fuente: AEMPS.
Indicaciones
Para el tratamiento del estreñimiento crónico. Atolaxant también es efectivo en el tratamiento de impactación fecal, definido como el estreñimiento refractario con acumulación fecal en el recto o en el colón.
Contraindicaciones
Obstrucción o perforación intestinal debido a trastornos estructurales o funcionales de la pared del intestino, íleo y condiciones de inflamación aguda del tracto intestinal, tales como la enfermedad de Crohn, la colitis ulcerosa y el megacolon tóxico. Hipersensibilidad a los principios activos o a alguno de los excipientes, incluidos en la sección 6.1.
Dosis para adultos
Posología Estreñimiento crónico. El periodo de tratamiento del estreñimiento crónico con Atolaxant normalmente no supera las 2 semanas, si bien se puede repetir si es necesario. Al igual que para todos los laxantes, el uso prolongado normalmente no está recomendado. Se puede extender el uso cuando sea necesario en el caso de pacientes con estreñimiento crónico grave o resistente, secundario a esclerosis múltiple o enfermedad de Parkinson, o inducida por medicamentos astringentes en particular opiáceos y antimuscarínicos. Adultos, adolescentes y pacientes de edad avanzada: de 1 a 3 sobres al día en dosis divididas, según la respuesta individual. Para un uso más prolongado, la dosis se puede ajustar a uno o dos sobres al día. Niños menores de 12 años de edad : No recomendado. Impactación fecal: La duración del tratamiento para la impactacion fecal con Atolaxant normalmente no debe exceder los 3 días. Adultos, adolescentes y edad avanzada: 8 sobres al día, que se debe tomar en un período de 6 horas. Niños menores de 12 años de edad: no está recomendado. Pacientes con la función cardiovascular deteriorada: para el tratamiento de la impactacion fecal la dosis se debe dividir de forma que no se tome más de dos sobres en el transcurso de una hora. Pacientes con insuficiencia real: No es necesario un ajuste de dosis, para el tratamiento del estreñimiento o impactacion fecal Forma de administración Cada sobre se disolverá en 125 ml de agua. Para el tratamiento de la impactacion…
Seguridad
Contraindicaciones
Hypercalcemia of any cause
Hypercalciuria with stone disease risk
Active urolithiasis
Severe renal impairment (eGFR < 30 mL/min/1.73 m²)
Sarcoidosis and other granulomatous diseases with hypercalcemia
Hypersensitivity to drug components
Reacciones adversas graves
Hypercalcemia with depressed consciousness, nausea and nephrocalcinosis
Milk-alkali syndrome at high doses combined with dairy intake
Acute kidney injury
Soft tissue calcification on prolonged hypercalcemia
Reacciones adversas frecuentes
Constipation
Flatulence, belching
Nausea
Reacciones adversas poco frecuentes
Hypercalciuria at doses above 1500 mg elemental calcium daily
Acid rebound when used as antacid
Embarazo
No FDA category assigned. Use during pregnancy is acceptable at doses not exceeding physiological needs (1000 mg elemental calcium daily total intake). High doses are not used – risk of maternal hypercalciuria and placental calcification.
Lactancia
Calcium is an essential component of a lactating mother's diet. Calcium supplementation at physiological doses is safe and compatible with breastfeeding.
Preguntas frecuentes
What is Calcium carbonate used for?
Calcium carbonate is evaluated for the following indications with varying evidence strength: Postmenopausal osteoporosis (evidence tier A), Mild hypocalcemia (evidence tier A), Antacid therapy for mild dyspepsia (evidence tier B). See the full indication matrix with dosing and citations above on this page.
What are the side effects of Calcium carbonate?
Common side effects of Calcium carbonate (≥ 1 in 100): Constipation, Flatulence, belching, Nausea. See the Safety section for uncommon and serious reactions.
Is Calcium carbonate safe during pregnancy?
No FDA category assigned. Use during pregnancy is acceptable at doses not exceeding physiological needs (1000 mg elemental calcium daily total intake). High doses are not used – risk of maternal hypercalciuria and placental calcification.
Is Calcium carbonate compatible with breastfeeding?
Calcium is an essential component of a lactating mother's diet. Calcium supplementation at physiological doses is safe and compatible with breastfeeding.
Who should not take Calcium carbonate?
Calcium carbonate is contraindicated in: Hypercalcemia of any cause; Hypercalciuria with stone disease risk; Active urolithiasis; Severe renal impairment (eGFR < 30 mL/min/1.73 m²); Sarcoidosis and other granulomatous diseases with hypercalcemia. Full list in the Safety section.
more calcium means stronger bones
beyond 1500 mg daily, additional calcium offers no extra benefit and increases hypercalciuria and stone disease risk.
every woman over 40 needs calcium for osteoporosis prevention
the 2018 USPSTF found no benefit of prophylactic supplementation in asymptomatic women. Adequate dietary intake is usually enough; supplements are indication-based after risk assessment.
calcium and vitamin D alone treat osteoporosis
confirmed osteoporosis requires disease-modifying therapy (bisphosphonates, denosumab, romosozumab). Calcium and vitamin D are background components.