What is the recommended dosage for vitamin D (International Units) drops?

Vitamin D Drops Dosing Recommendations

Age-Based Dosing for Healthy Individuals

For infants up to 12 months of age, administer 400 IU daily; for children and adolescents ages 1-18 years, provide 400-600 IU daily; and for adults, give 600-800 IU daily for maintenance of adequate vitamin D status. 1

Infants (0-12 months)

• All infants require 400 IU (10 µg) daily starting in the first days of life, regardless of feeding method (breast milk, formula, or mixed feeding) 1, 2, 3
• This universal recommendation exists because breast milk contains insufficient vitamin D, and formula-fed infants rarely consume enough volume to meet requirements through formula alone 4
• Upper tolerable limit: 1000 IU/day for ages 0-6 months; 1500 IU/day for ages 7-12 months 1

Children and Adolescents (1-18 years)

• Standard maintenance dose: 400-600 IU daily 1, 5
• Age-specific upper limits to prevent toxicity:
  • Ages 1-3 years: 2500 IU/day maximum 1
  • Ages 4-8 years: 3000 IU/day maximum 1, 5
  • Ages 9-18 years: 4000 IU/day maximum 1

Adults (19+ years)

• Maintenance dose: 600 IU daily for adults under 70 years; 800 IU daily for adults over 60-70 years 1, 2
• Upper tolerable limit: 4000 IU/day for general population 1

Special Populations Requiring Higher Doses

Preterm Infants on Parenteral Nutrition

• Administer 200-1000 IU/day (or 80-400 IU/kg/day) depending on weight and clinical status 1
• These infants have higher requirements due to limited stores and rapid growth 1

Patients with Malabsorption Conditions

• Require 4000-5000 IU daily for 2 months to achieve adequate levels, then maintenance dosing 1, 6
• This includes inflammatory bowel disease, post-bariatric surgery, chronic liver disease, pancreatic insufficiency, and chronic intestinal failure 1, 6
• Post-bariatric surgery patients specifically need at least 3000 IU daily, titrated to achieve 25(OH)D ≥30 ng/mL 6

Patients on Enteral or Parenteral Nutrition

• Enteral nutrition should provide at least 1000 IU per day in 1500 kcal 1
• Parenteral nutrition should provide at least 200 IU per day 1
• These patients have higher requirements due to underlying illness and poor baseline status 1

Treatment of Documented Vitamin D Deficiency

Standard Deficiency Correction Protocol

For documented deficiency (25(OH)D <20 ng/mL), treat with 50,000 IU weekly for 8 weeks, then transition to maintenance dosing of 1500-2000 IU daily. 6, 3

• This loading dose approach is the standard treatment for adults with confirmed deficiency 6, 3
• After 8 weeks, recheck 25(OH)D levels at 6-12 weeks to confirm adequate response 5, 6
• Target serum 25(OH)D concentration should be >50 nmol/L (20 ng/mL) at minimum 1, 5

Severe Deficiency (25(OH)D <5 ng/mL)

• Administer ergocalciferol 50,000 IU weekly for 12 weeks, then monthly thereafter 1
• This more prolonged regimen is needed when rickets or osteomalacia may be present 1

Recurrent Deficiency

• Use 4000-5000 IU daily for 2 months to achieve blood levels of 40-60 ng/mL 1
• Substantially higher doses may be required depending on severity 1
• Monitor frequency based on severity of deficiency and dose required 1

Critical Monitoring Parameters

Baseline Assessment

• Measure 25(OH)D, calcium, phosphorus, alkaline phosphatase, and parathyroid hormone before initiating treatment 6
• This establishes baseline status and identifies concurrent abnormalities 6

Follow-Up Monitoring

• Recheck 25(OH)D levels after 6-12 weeks of treatment to assess response 5, 6
• For patients on long-term parenteral nutrition, monitor periodically for deficiency 1
• In patients with 25(OH)D <50 nmol/L, provide additional supplementation 1

Target Levels

• Minimum sufficiency: 25(OH)D >50 nmol/L (20 ng/mL) 1, 5, 3
• Some guidelines recommend higher targets of 75 nmol/L (30 ng/mL) for optimal health 6, 7

Safety Considerations and Toxicity

Toxicity Thresholds

• Vitamin D toxicity is rare but occurs with prolonged daily intake >10,000 IU or serum 25(OH)D >375 nmol/L 1, 6
• Toxicity manifests as hypercalcemia, hypercalciuria, dizziness, and potential renal failure 1, 6
• Prolonged daily intake up to 10,000 IU or serum concentrations up to 240 nmol/L appears safe 1

Age-Specific Upper Limits (Critical to Avoid Toxicity)

• Never exceed age-appropriate upper limits as outlined above 1, 5
• A proposed dose of 60,000 IU weekly (equivalent to 8,571 IU/day) would far exceed the 3,000 IU/day upper limit for children ages 4-8 years and poses significant toxicity risk 5

Common Clinical Pitfalls to Avoid

Do Not Use Active Vitamin D for Nutritional Deficiency

• Calcitriol or other 1-hydroxylated vitamin D sterols should NOT be used to treat nutritional vitamin D deficiency 1, 6
• Reserve active vitamin D analogs for specific conditions like chronic kidney disease 1, 6

Ensure Adequate Calcium Intake

• Provide 1200-1500 mg calcium daily during vitamin D treatment, as vitamin D enhances calcium absorption 6
• Without adequate calcium, vitamin D supplementation may mobilize calcium from bone 6

Formulation Considerations

• Cholecalciferol (vitamin D3) demonstrates higher bioefficacy than ergocalciferol (vitamin D2) for treating deficiency 6
• However, ergocalciferol may be safer in certain populations and is the standard for high-dose treatment protocols 1
• Available formulations include 400 IU over-the-counter and 50,000 IU prescription capsules 1, 8

Oral Supplementation During Parenteral Nutrition

• Consider oral vitamin D supplementation in patients on partial PN and during weaning from PN 1
• This prevents deficiency as enteral intake increases 1

High-Dose Bolus Approach Is Ineffective

• Avoid single ultra-high loading doses (e.g., 540,000 IU) without maintenance dosing, as this approach has been shown ineffective 1
• Daily or weekly dosing shows superior protective effects, especially in severe deficiency 1