What is the treatment for Vitamin D deficiency using Inj Arachitol (Vitamin D3)?

Treatment of Vitamin D Deficiency with Injectable Arachitol (Vitamin D3)

For vitamin D deficiency, intramuscular Arachitol (cholecalciferol 600,000 IU) is a safe and effective single-dose option specifically for patients with malabsorption syndromes, particularly post-bariatric surgery patients, where it significantly outperforms oral supplementation in achieving and maintaining target vitamin D levels. 1, 2, 3

When Injectable Arachitol is Indicated

Intramuscular vitamin D3 is the preferred route for patients with documented malabsorption who fail oral supplementation, including:

• Post-bariatric surgery patients (especially Roux-en-Y gastric bypass or biliopancreatic diversion) 1, 2, 3
• Inflammatory bowel disease (Crohn's disease, ulcerative colitis) 1
• Short bowel syndrome 1
• Pancreatic insufficiency 1
• Untreated celiac disease 1

IM administration results in significantly higher 25(OH)D levels and lower rates of persistent vitamin D deficiency compared to oral supplementation in these populations. 1, 2, 3

Dosing Protocol for Injectable Arachitol

Single Megadose Regimen

Administer 600,000 IU cholecalciferol (Arachitol) as a single intramuscular injection, which has been proven safe and effective in post-bariatric surgery patients. 3

• This single injection significantly increases vitamin D levels from baseline (61.5 nmol/L) to peak at 3 months (100.5 nmol/L) 3
• Elevated levels persist for 6 months post-injection (79.1 nmol/L), with gradual decline by 9-12 months 3
• 93-100% of patients achieve normalized vitamin D levels at all time points up to 12 months 3

Maintenance Strategy

Continue oral vitamin D supplementation (at least 2,000 IU daily) alongside the injection to maintain long-term adequacy, as the single injection effect diminishes after 6-9 months. 1, 3

Monitoring Protocol

Measure 25(OH)D levels at the following intervals:

• Baseline (before injection) 3
• 3 months post-injection (to confirm adequate response) 1, 2, 3
• 6 months post-injection 3
• 12 months post-injection (to determine need for repeat dosing) 3

Target 25(OH)D level is at least 30 ng/mL (75 nmol/L) for optimal anti-fracture efficacy. 1, 2

Safety Considerations

The 600,000 IU single IM dose has an excellent safety profile:

• No cases of hypercalcemia were observed in clinical studies 3
• Ionized calcium remained within normal limits throughout 12-month follow-up 3
• Parathyroid hormone (PTH) levels remained stable 3
• Bone mineral density showed no adverse changes 3

However, avoid single ultra-high loading doses exceeding 600,000 IU without maintenance dosing, as doses above 300,000-540,000 IU may be inefficient or potentially harmful for fall and fracture prevention. 1, 4

Essential Co-Interventions

Ensure adequate calcium intake of 1,000-1,500 mg daily from diet plus supplements if needed, as calcium is necessary for clinical response to vitamin D therapy. 1, 2

• Take calcium supplements in divided doses of no more than 600 mg at once for optimal absorption 1, 2

Alternative Approach When IM is Unavailable

If IM Arachitol is not accessible (availability varies by country), use substantially higher oral doses for malabsorption:

• 4,000-5,000 IU cholecalciferol daily for 2 months 1
• Or 50,000 IU cholecalciferol 1-3 times weekly for severe malabsorption 1
• Post-bariatric surgery patients require at least 2,000 IU daily maintenance to prevent recurrent deficiency 1

Oral calcifediol [25(OH)D] may serve as an effective alternative when IM is contraindicated (anticoagulation, infection risk) due to higher intestinal absorption rates. 1

Critical Pitfalls to Avoid

Never use active vitamin D analogs (calcitriol, alfacalcidol, doxercalciferol, paricalcitol) to treat nutritional vitamin D deficiency, as they bypass normal regulatory mechanisms, do not correct 25(OH)D levels, and carry higher risk of hypercalcemia. 1, 2

Do not rely solely on the single injection without oral maintenance supplementation, as vitamin D levels decline significantly after 6-9 months and require ongoing supplementation. 3

Ensure compliance with oral supplementation is addressed, as poor adherence is the most common reason for inadequate response in malabsorption patients. 1

Expected Outcomes

With the 600,000 IU IM injection plus oral supplementation:

• 93-100% of patients achieve normalized vitamin D levels 3
• Levels peak at 3 months and remain elevated through 6 months 3
• Anti-fall efficacy begins at 25(OH)D levels ≥24 ng/mL 1, 2
• Anti-fracture efficacy requires levels ≥30 ng/mL 1, 2