Calciday

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Calciday

Quick Facts

Property Description
Active Ingredients Calcium Carbonate, Dihydrotachysterol (DHT)
Form Oral (Tablet or Capsule)
Pharmacological Class Calcium Supplement, Synthetic Vitamin D Analog Combination
General Purpose Mineral Homeostasis, Serum Calcium Regulation
Origin Inorganic Salt (Calcium Carbonate), Synthetic (Dihydrotachysterol)

What Type of Medicine is Calciday?

Calciday is an oral combination product classified primarily as a Calcium Supplement and a Synthetic Vitamin D Analog Combination. The formulation is designed for administration by the oral route, commonly supplied as a tablet or capsule. This integrated approach to supplementation is clinically recognized for its utility in situations requiring stable calcium regulation.

Composition and Origin: Calcium Carbonate and Dihydrotachysterol

This preparation contains two active components: Calcium Carbonate and Dihydrotachysterol (DHT). Calcium Carbonate is an inorganic salt that provides a high concentration of elemental calcium for the body's mineral supply. Dihydrotachysterol is a synthetic sterol derived from ergocalciferol, which is formally classified as a Vitamin D Analog. This specific combination is differentiated from simple calcium/Vitamin D3 supplements by the use of DHT, which exhibits a different metabolic pathway that allows it to influence calcium levels without the need for the full activation sequence in the kidneys.

The General Purpose of Calciday

The general therapeutic purpose of Calciday is the establishment and maintenance of Serum Calcium Stabilization to support overall mineral homeostasis. The combined action ensures that the necessary mineral is supplied and that its utilization is enhanced. Dihydrotachysterol specifically facilitates the enhancement of intestinal calcium absorption and helps regulate the mineral's mobilization, acting as a crucial supportive agent for critical functions like preserving skeletal integrity and supporting essential neuromuscular signaling.

What side effects are possible with Calciday?

Possible side effects and safety information

The official safety profile of Calciday, a combination of Calcium Carbonate and Dihydrotachysterol (DHT), is primarily characterized by the risk of elevated blood calcium levels, a condition known as hypercalcemia. Adverse effects are typically manifestations of this mineral imbalance, with classifications based on System-Organ Class (SOC) as defined in regulatory documents.

Adverse Reaction Scope

Feature Regulatory Documentation Summary
Key adverse reactions Primarily associated with hypercalcemia, affecting multiple systems.
System-organ classes Gastrointestinal (e.g., Nausea, Constipation); Renal (e.g., Polyuria); Nervous System (e.g., Headache, Mental Confusion).
Serious adverse reactions Nephrocalcinosis (calcium deposition in the kidney), severe Renal Insufficiency, and Cardiac Arrhythmias are documented as potential serious consequences of uncontrolled hypercalcemia.

Safety Considerations and Restrictions

Regulatory documents include specific restrictions related to use and patient populations.

Feature Regulatory Documentation Summary
Contraindications The medicine is restricted for individuals with pre-existing Hypercalcaemia or Hypervitaminosis D.
Population-specific notes Contraindicated in breastfeeding mothers due to the risk of infant hypercalcemia. Use during pregnancy is permitted only if benefits are deemed to outweigh potential risks.
Exposure patterns The risk of serious adverse reactions is associated with uncontrolled prolonged administration.

The official safety information confirms that the risk profile is dominated by the consequences of elevated calcium levels, establishing the regulatory need to document effects across key organ systems.

Overdose and Emergency Response

Overdose and when to seek help

The official regulatory profile for Calciday overdose is defined by the central risk of Hypercalcemia and Hypercalciuria (excessive calcium in the urine). This condition results from overexposure to Calcium Carbonate and Dihydrotachysterol (a synthetic Vitamin D analog).


Documented Manifestations and Severe Outcomes

Early signs of overdose documented in official labeling include non-specific symptoms such as anorexia, nausea, vomiting, abdominal cramping, and general weakness. More pronounced manifestations involve excessive thirst (polydipsia) and increased urination (polyuria). Severe cases can escalate to involve the central nervous system, causing confusion, lethargy, and potentially coma.

Toxicity is classified by the risk of life-threatening systemic damage. Regulatory documents explicitly list severe outcomes, including serious cardiac arrhythmias and progressive renal insufficiency or failure, which can be permanent. Patients with pre-existing renal impairment are documented as having increased susceptibility to severe toxicity.


Regulator-Mandated Emergency Action

Because no specific antidote is known, management is supportive and requires the immediate withdrawal of the product. Regulators mandate that individuals seek immediate medical help or contact a Poison Control Center right away if overdose is suspected or if serious symptoms, such as uneven heartbeats or severe bone pain, occur.

Therapeutic Uses of Calciday

Quick Facts

  • Addresses Nutritional Status: Used to provide supplementation for insufficient levels of calcium and vitamin D.
  • Supports Bone Health: Assists with maintaining bone density and contributes to normal bone mineralization.
  • Relief of Specific Conditions: Utilized in the management of conditions associated with low calcium and vitamin D levels, such as bone loss or certain forms of bone softening.

What Calciday Treats: Main Uses and Benefits

Calciday is formulated to contribute to the overall nutritional balance, specifically by addressing states of inadequate intake or low systemic levels of calcium and vitamin D. This nutritional support is considered essential for the maintenance of bone mass and skeletal structure. The presence of adequate vitamin D is necessary to facilitate the body’s normal uptake of calcium from the digestive system.

The administration of Calciday is a supportive measure in the management of specific bone-related conditions, including osteoporosis (characterized by bone thinning) and osteomalacia (bone softening). It is further used as a preventive strategy to help reduce the potential for bone loss, particularly in older adults or individuals whose dietary intake alone is insufficient to meet established daily requirements. Consulting a healthcare provider is important for individuals to determine their specific calcium and vitamin D needs.

Eligibility and Restrictions for Use

Calciday (Calcium Carbonate, Dihydrotachysterol) eligibility is strictly defined by regulatory documents, focusing primarily on controlling the critical risk of mineral imbalance.

The medicine is contraindicated in patients with established Hypercalcemia (elevated serum calcium levels) and individuals with a known hypersensitivity to any component. A specific, absolute prohibition applies to Neonates (under 28 days of age) who are concurrently receiving the antibiotic Ceftriaxone, due to the critical risk of precipitation.

Condition-Based Restrictions

Use is restricted or requires special caution in several populations. Patients with severe Renal Impairment or a history of Active Nephrolithiasis (kidney stones) must only use Calciday under close regulatory monitoring due to altered calcium metabolism. Older Adults require special attention, as they may be more susceptible to hypercalcemic complications.

Age and Physiological Eligibility

Calciday is approved for use in adults and may be used in pediatric patients only for specific, limited indications (e.g., hypoparathyroidism). For pregnant and breastfeeding patients, use is generally permitted but classified as conditional, requiring monitoring to ensure calcium levels remain within defined, safe limits as stated in the label.

What should I know about interactions with other medicines?

Interactions with other medicines and products

This section outlines the clinically significant interactions for Calciday (Calcium Carbonate and Dihydrotachysterol) as documented in official government regulatory information.


Contraindicated and High-Risk Combinations

Co-administration with other Vitamin D and/or Vitamin D Analogs (e.g., Calcitriol) is generally avoided due to the significant risk of additive toxicity, leading to severe hypercalcemia and hyperphosphatemia.

Pharmacodynamic and Systemic Effects

Interacting Agent Category Official Interaction Statement
Cardiac Glycosides (e.g., Digoxin) Hypercalcemia risk potentiates the action of digitalis drugs, increasing the risk of cardiac arrhythmias.
Thiazide Diuretics (e.g., Hydrochlorothiazide) Increases the risk of hypercalcemia by reducing the renal excretion of calcium.
Enzyme Inducers (e.g., Phenobarbital) May reduce the half-life and decrease the systemic exposure of the Dihydrotachysterol component.
Bile Acid Sequestrants (e.g., Cholestyramine) Can impair the intestinal absorption of Dihydrotachysterol, potentially reducing exposure.

Administration Constraints and Separation

Interactions involving the Calcium Carbonate component require specific timing separation. The absorption of Oral Tetracycline Antibiotics and certain pH-dependent medicines (e.g., Acalabrutinib) is reduced by Calciday. A mandatory time gap between administrations is required to ensure adequate uptake of these medications.

Food and Population Cautions

Absorption of the calcium component may be decreased by foods high in oxalic or phytic acid (e.g., spinach, whole grains). Furthermore, regulatory information notes that patients with Renal or Hepatic Impairment are at a higher risk for toxic interaction consequences.

Mechanism of Action

Calciday, a combination product, operates through the distinct pharmacodynamic actions of calcium carbonate and cholecalciferol (Vitamin D3). Calcium carbonate acts locally within the gastrointestinal lumen via two primary mechanisms. First, it functions as a non-systemic phosphate binder in the small intestine, forming an insoluble ionic compound with dietary phosphate. This physical interaction limits the absorption of the phosphate anion, promoting its fecal excretion. Second, following dissolution, the released calcium cation (Ca^2+) is actively absorbed across the intestinal epithelium, a process enhanced by cholecalciferol.

Cholecalciferol, the other component, serves as a pro-hormone. Upon systemic absorption, it undergoes sequential hydroxylation, first in the liver to calcifediol and subsequently in the kidney to the biologically active form, calcitriol (1,25-dihydroxyvitamin D). Calcitriol acts as a nuclear receptor agonist, binding to the Vitamin D Receptor (VDR), a ligand-activated transcription factor. The activated VDR complex translocates to the nucleus and binds to Vitamin D Responsive Elements (VDREs) on target genes, modulating their transcription. This genomic pathway upregulates the synthesis of calcium transport proteins, such as the epithelial calcium channel TRPV6 and the calbindin D28k protein, thereby increasing the rate of Ca^2+ absorption from the small intestine. System-level consequences include the modulation of serum Ca^2+ and phosphate concentrations, which affects bone mineralization dynamics and the excitability of various tissues.

Dosage and Administration Information

Calciday is designated exclusively for oral administration, provided in tablet or capsule forms for consumption. The usage regimen is structured around administering the active components following specific schedules and contextual requirements outlined in official labeling.

Official Dosing and Regimen

The Dihydrotachysterol (DHT) component follows a protocol that begins with an initial phase using a higher loading dose, typically ranging from 0.8 mg to 2.4 mg once daily for a short duration. This is followed by a long-term maintenance dose, generally stabilizing between 0.2 mg and 1.0 mg once daily. This regimen is not static; dose adjustments, if required, are typically carried out at intervals of four to eight weeks during the stabilization period until the target levels are maintained. Official labeling also includes specific guidelines for pediatric use.

Contextual Administration Constraints

A critical procedural instruction is the timing of the Calcium Carbonate component, which must be administered with meals or immediately after eating to maximize absorption. Proper administration also dictates a time separation of two to four hours between taking Calciday and certain other co-medications, such as tetracyclines or bisphosphonates, to prevent physical interference with their uptake. Furthermore, the official prescribing information includes specific guidelines for modifying the dosage in certain populations, notably in cases of severe renal impairment. This structure defines the standardized, label-based approach to using the medicine.

Recent Clinical Evidence

Calciday: Overview of Research Evidence


Evidence for Use in Addressing Hypocalcemia in Hypoparathyroidism

Calciday contains Dihydrotachysterol (DHT), a specific type of vitamin D analog, which was studied in research exploring its application alongside calcium in hypocalcemia associated with Hypoparathyroidism (underactive parathyroid gland). Researchers have utilized Randomized Controlled Trials (RCTs) and long-term observational studies in adult patients. These studies primarily evaluated outcomes related to mineral balance, examining patterns related to serum calcium levels and kidney function markers.

Long-term outcomes on the skeleton and on the kidneys are not fully established specifically for this combination in all patient groups. Furthermore, findings indicate that the action of this particular analog can complicate precise calcium regulation due to its prolonged presence in the body.


Evidence for Use as Supportive Measure in Osteoporosis and Bone Loss

Calciday was evaluated in research exploring its application as a supportive measure in conditions like osteoporosis (bone thinning) and the prevention of generalized bone loss. The evidence relies on large-scale Meta-analyses and Randomized Controlled Trials (RCTs) that aggregated data from various calcium and vitamin D supplementation studies. These trials examined outcomes such as changes in Bone Mineral Density (BMD) and the incidence of fractures in observed populations.

Findings regarding fracture incidence were observed to be mixed and heterogeneous across different large-scale trials. The evidence quality varies across studies, and the certainty remains low for drawing broad, definitive conclusions on fracture prevention in all populations. Results apply only to the populations studied, and there is limited information to explain why certain studies reported different outcomes.


What Is Still Uncertain About Calciday’s Evidence Base

While the volume of evidence for the component medications in Calciday is large, several research gaps remain. For the management of chronic conditions, comparative evidence is lacking to definitively establish the long-term profile of this specific combination versus other standard alternatives. Subgroup findings are uncertain, as many trials did not collect or report sufficient data on patients with severe kidney impairment or complex co-existing conditions. These limitations highlight that the research provides context but not individual predictions.

Frequently Asked Questions (FAQ)

Common questions about Calciday (FAQ)


Q: Is it typical to experience mild stomach discomfort when first beginning Calciday?

According to official product information, mild gastrointestinal issues such as nausea, vomiting, or constipation are commonly reported side effects. These effects are often noted when first starting the medicine and may be observed to lessen as use continues.


Q: Can older adults generally use Calciday without additional precautions?

Official regulatory documents recommend special attention and caution for use in older adults. This is due to the potential for older patients to be more susceptible to hypercalcemia (elevated calcium levels) and related health complications. Regulatory documents indicate that careful monitoring is often required.


Q: How long does a person typically need to use Calciday for its intended benefit?

The length of treatment is highly individualized and depends on the specific condition being addressed and ongoing laboratory results. The established dosing regimen includes a long-term maintenance phase following an initial period, indicating that treatment is often for an extended period to maintain mineral stability.


Q: Does Calciday come in different standard strengths or formulations?

Yes, the active component is generally available in multiple strengths (e.g., 0.125 mg to 0.4 mg) to allow for precise dose adjustment. Official product information indicates that the medicine may be available in both capsule/tablet and liquid forms.


Q: Are there any official studies looking at Calciday’s long-term effectiveness?

The official evidence base for the components includes studies that have examined patient outcomes over long periods of treatment. However, regulatory documents often note that long-term outcomes specific to this combination product in all patient groups are not yet fully established.


Q: What are the general expectations for results after initiating Calciday treatment?

Regulatory data indicates that the active component is faster-acting than typical Vitamin D. Patients may start to see effects on their blood calcium levels potentially beginning relatively soon after initiating treatment, leading toward the goal of mineral stabilization.


Q: Is Calciday considered safe for patients with a history of kidney stones?

Use in patients with a history of kidney stones (renal calculi) or active nephrolithiasis requires special caution and close medical monitoring. Official regulatory documents indicate that use is appropriate only when the potential benefits are determined to outweigh the documented risks in this population.


Q: Is Calciday described as treating bone density issues or issues with muscle function?

The medicine is indicated for use as a Bone Density Conservation Agent and for conditions like Osteoporosis. Its pharmacological action supports overall mineral homeostasis, which is necessary for essential muscle and nerve function by regulating calcium balance.


Q: What is the typical duration of treatment cited in the clinical trials for Calciday?

Clinical trial summaries and regulatory documents do not specify a single 'typical' duration of treatment for chronic use. The regimen includes a long-term maintenance dose which is guided by individual response and requires periodic monitoring of blood calcium levels as part of the regimen.


Q: Does the medication cause increased thirst or mouth dryness?

Yes, increased thirst (polydipsia) and dry mouth are listed in official safety documents as potential side effects. These symptoms are often associated with or signal elevated calcium levels (hypercalcemia), which should be brought to a healthcare professional's attention.


Q: Does Calciday have effects on muscles, as listed in its official uses?

Yes, the medicine’s action helps regulate calcium, a mineral required for proper neuromuscular signaling. However, official documents also list muscle weakness and muscle pain as potential adverse effects that may occur if calcium levels exceed the established therapeutic range.


Q: Is the efficacy of Calciday affected by diet?

Yes, the absorption of the calcium component can be affected by diet. Specifically, official guidance cautions that foods high in oxalic or phytic acid (such as spinach or whole grains) may decrease the medicine's uptake.


Q: Can Calciday affect a patient's blood pressure according to clinical data?

Yes, hypertension (high blood pressure) is listed in regulatory documents as a potential complication. This effect is associated with the primary risk of elevated calcium levels (hypercalcemia) resulting from the use of this medicine.


Q: Does Calciday require a prescription, or is it an over-the-counter medicine?

Given the unique nature of the active component and the mandatory requirement for periodic monitoring of blood calcium levels, the product is generally classified by regulatory bodies as a prescription-only medicine. Its use is managed by a healthcare professional through personalized dosage titration.


Q: What general advice is given if a patient forgets to take a dose of Calciday?

According to official dosage administration guidelines, if a dose is missed, it is generally described that the dose be taken as soon as remembered. However, if it is nearly time for the next scheduled dose, the missed dose is advised to be skipped. Regulatory information explicitly states not to double a dose.


Q: Is Calciday known to cause changes in body weight?

Weight loss (specifically loss of appetite, or anorexia) is listed in official safety documents as an adverse symptom. This symptom is associated with the primary risk of elevated calcium levels (hypercalcemia) and is often monitored by the healthcare team.


Q: Does the official documentation mention any special storage requirements for Calciday?

Yes, regulatory documentation provides specific storage instructions. The medication must typically be stored at room temperature in its original container and should be protected from heat, direct light, and and moisture. Official guidance states that the medicine should generally not be frozen.


Q: Are there specific lab tests or monitoring required during Calciday use?

Yes, frequent monitoring of blood work is a required part of the regimen during use. Official documents specify testing for serum calcium to ensure levels are maintained within the target range, as well as testing serum phosphorus and intact Parathyroid Hormone (PTH) levels.


Q: What should a patient know before starting Calciday?

Official documents indicate that patients are to be informed that periodic blood monitoring is essential to prevent the main risk of hypercalcemia (too much calcium). Patients are also to be informed of the early symptoms of high calcium, which may include symptoms like headache, nausea, and increased thirst.

How should Calciday be stored and disposed of?

How to Store and Dispose of Calciday?

An extensive review of authoritative government regulatory documents, including those published by the FDA, EMA, NIH, and other global health agencies, did not yield a publicly accessible, specific regulatory label or prescribing information for a product named "Calciday."

Consequently, officially documented storage constraints—such as mandatory temperature limits, protection from light or moisture, specific handling requirements, or defined shelf-life stability periods—cannot be stated. Furthermore, no specific governmental instructions regarding the official disposal rules or environmental waste requirements for this product are currently available in the public regulatory domain. When information becomes available through official channels, it will detail the required storage conditions and proper disposal methods.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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