Hidroferol Wekelijks (Calcifediol Monohydrate)

Hidroferol Wekelijks is indicated for the prevention and treatment of vitamin D deficiency in individuals who require regular supplementation.

• Adults with low serum 25‑hydroxyvitamin D levels.
• Children and adolescents with documented deficiency.
• Patients with conditions that limit cutaneous vitamin D synthesis, such as limited sun exposure or malabsorption.
• Individuals at risk of osteomalacia or rickets due to inadequate vitamin D intake.
• Elderly persons with reduced dietary vitamin D intake.

• Calcifediol monohydrate is the 25‑hydroxylated form of vitamin D3. After oral absorption, it is directly converted to 25‑hydroxyvitamin D in the circulation, bypassing hepatic 25‑hydroxylation. The circulating 25‑hydroxyvitamin D binds to vitamin D‑binding protein and is later converted by renal 1α‑hydroxylase to the active hormone 1,25‑dihydroxyvitamin D, which regulates intestinal calcium and phosphate transport through the vitamin D receptor (VDR) in target cells and bone remodeling.

Adverse reactions to Hidroferol Wekelijks are generally mild, but rare serious events have been reported.

Common

• Mild gastrointestinal discomfort such as nausea, abdominal cramping, or loss of appetite.
• Transient headache that resolves without intervention.
• Slight, asymptomatic increase in serum calcium levels detected on routine testing.
• General fatigue or drowsiness, especially after the first weekly dose.

Serious

• Clinically significant hypercalcemia manifested by excessive thirst, frequent urination, constipation, or cardiac rhythm disturbances.
• Allergic reactions ranging from skin rash and pruritus to angioedema and, rarely, anaphylaxis.
• Development of renal calculi in patients with pre‑existing risk factors for stone formation.
• Severe hypervitaminosis D leading to ectopic calcification in soft tissues, including blood vessels and the kidneys.

Precautions for using Hidroferol Wekelijks focus on patient conditions that may affect vitamin D metabolism or increase the risk of calcium imbalance.

• Assess baseline serum 25‑hydroxyvitamin D and calcium before initiating therapy.
• Use with caution in patients with renal impairment, hyperparathyroidism, or granulomatous diseases.
• Avoid in individuals with known hypersensitivity to calcifediol or any excipients.
• Monitor calcium and phosphate levels periodically during long‑term use.
• Consider dose adjustment or medical supervision in elderly patients or those taking multiple supplements.
• Do not exceed the recommended weekly dose without physician guidance.

Hidroferol Wekelijks can interact with certain medicines that influence calcium balance or vitamin D metabolism.

Avoid

• Concomitant use with high‑dose vitamin D supplements that could cause excessive serum 25‑hydroxyvitamin D.
• Co‑administration with thiazide diuretics, which may increase the risk of hypercalcemia.

Use with caution

• Calcium carbonate or other calcium‑containing antacids, as they may augment calcium absorption.
• Bisphosphonates or denosumab, because combined effects on bone turnover require monitoring.
• Corticosteroids, which can impair vitamin D activation and alter calcium homeostasis.
• Certain anticonvulsants (e.g., phenytoin, phenobarbital) that increase vitamin D catabolism.
• Orlistat, which may reduce absorption of fat‑soluble vitamins including vitamin D.