What is the recommended treatment for vitamin D (Vit D) deficiency?

Vitamin D Deficiency Treatment

For vitamin D deficiency, treatment with oral vitamin D supplementation of 50,000 IU weekly for 4-8 weeks followed by maintenance therapy of 800-1,000 IU daily is recommended. 1

Diagnosis and Classification

• Vitamin D status is determined by measuring serum 25-hydroxyvitamin D [25(OH)D] levels:
  • Severe deficiency: <5 ng/mL
  • Mild deficiency: 5-15 ng/mL
  • Insufficiency: 16-30 ng/mL
  • Optimal range: 30-80 ng/mL 1

Treatment Protocol Based on Deficiency Severity

For Mild Insufficiency (25(OH)D 15-20 ng/mL)

• Start with 800-1,000 IU of vitamin D daily 1
• Cholecalciferol (vitamin D3) is preferred over ergocalciferol (vitamin D2) due to higher bioefficacy 1

For Mild Deficiency (25(OH)D 5-15 ng/mL)

• Administer 50,000 IU weekly for 4-8 weeks 1
• Follow with maintenance dose of 800-1,000 IU daily 1, 2

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

• Requires individualized treatment under close monitoring 1
• A cumulative dose of at least 600,000 IU administered over several weeks appears necessary to replenish vitamin D stores 3
• Avoid single large doses of 300,000-500,000 IU 3

Special Populations Requiring Higher Doses

Certain populations require specialized approaches with higher vitamin D doses:

• Obesity: 2-3 times higher doses (up to 7,000 IU daily) 1, 4
• Elderly (≥65 years): Minimum 800 IU daily 1
• Malabsorption syndromes/Bariatric surgery: Minimum 2,000 IU daily or weekly regimens 1, 4
• Liver disease: Higher doses due to impaired hepatic 25-hydroxylation 1, 4
• Chronic kidney disease: Specialized approaches with ergocalciferol supplementation 1
• Dark-skinned or veiled individuals: 800 IU/day 1
• Institutionalized individuals: 800 IU/day 1

Monitoring and Safety

• Recheck 25(OH)D levels 3-4 months after initiating therapy 1
• Target range for 25(OH)D levels: 30-80 ng/mL 1
• Monitor serum calcium and phosphorus during supplementation 1
• Vitamin D toxicity is rare but can occur with doses >10,000 IU daily for extended periods 1
• Toxicity is indicated by 25(OH)D levels >150 ng/mL 1

Important Precautions

• Caution in patients taking thiazide diuretics due to potential hypercalcemia 5
• Mineral oil interferes with vitamin D absorption 5
• Adequate calcium intake (1000-1500 mg daily) is necessary alongside vitamin D supplementation 1
• Vitamin D administration from all sources (fortified foods, supplements, prescriptions) should be evaluated to prevent overdosing 5
• Caution in pregnancy: safety of doses exceeding 400 IU daily during pregnancy has not been established 5

Practical Approach to Treatment

1. Measure baseline 25(OH)D level
2. Select appropriate regimen based on severity of deficiency
3. For most adults with deficiency (<20 ng/mL), use 50,000 IU weekly for 8 weeks 2
4. After normalization, maintain with 800-1,000 IU daily 2
5. For high-risk groups (obesity, malabsorption, etc.), consider higher maintenance doses
6. Recheck levels after 3-4 months of therapy
7. Adjust dose as needed to maintain 25(OH)D levels between 30-80 ng/mL

The recommended approach balances efficacy and safety while addressing the specific needs of different patient populations.