What is the recommended vitamin D level and supplementation for individuals with a positive COVID-19 test?

Vitamin D Recommendations for Individuals with Positive COVID-19 Tests

For individuals with a positive COVID-19 test, a target blood level of vitamin D of at least 50 nmol/L (20 ng/mL) is recommended, with a preferred range of 40-60 ng/mL (100-150 nmol/L), which may require supplementation of 800-1000 IU/day for most individuals. 1, 2

Vitamin D Status and COVID-19 Relationship

• Multiple observational studies have demonstrated an inverse relationship between serum 25-hydroxyvitamin D (25(OH)D) concentrations and COVID-19 risk and severity 2, 3
• Individuals with vitamin D levels <20 ng/mL have been shown to have higher SARS-CoV-2 positivity rates (12.5%) compared to those with sufficient levels (8.1%) 3
• Vitamin D deficiency has been associated with:
  • Increased inflammatory responses
  • Impaired immune function
  • Potentially worse outcomes in COVID-19 patients 4

Recommended Supplementation Protocol

For General Population with COVID-19:

• 800-1000 IU/day of vitamin D supplementation 1
• This aligns with the European Society for Clinical Nutrition and Metabolism (ESPEN) recommendation for maintaining adequate nutrient intake during infections 5

For Individuals Likely to be Deficient:

• Consider a higher initial dose of 4000 IU/day for the first four weeks before reducing to 800-1000 IU/day 1
• This applies particularly to:
  • Dark-skinned or veiled individuals with limited sun exposure 6
  • Institutionalized individuals 6
  • Older adults (≥65 years) 6, 5
  • Those with obesity or chronic diseases 5

Hospitalized COVID-19 Patients:

• Vitamin D status should be checked upon admission 1
• Supplementation should be provided based on measured levels 1
• Consider more aggressive correction of deficiency in moderate-to-severe cases 2

Target Blood Levels

• Minimum target: 50 nmol/L (20 ng/mL) 1
• Preferred range: 40-60 ng/mL (100-150 nmol/L) 2, 7
• Safety upper limit: 80 ng/mL (not to be targeted but considered safe) 6

Nutritional Considerations Beyond Vitamin D

• Ensure adequate overall nutrition with:
  • Energy intake: 27-30 kcal/kg body weight/day 5
  • Protein intake: 1.0-1.3 g/kg body weight/day 5
  • Balanced fat and carbohydrate intake 5
• Screen for malnutrition using validated tools, as nutritional status impacts COVID-19 outcomes 5
• Consider zinc status, as lower zinc levels have been observed in COVID-19 patients 4

Important Caveats and Considerations

• Vitamin D supplementation appears to be most beneficial when correcting deficiency rather than providing supraphysiologic doses 5
• While evidence suggests vitamin D may help reduce COVID-19 severity, it should be considered as part of comprehensive care, not as a standalone treatment 2
• Dosing regimens should avoid extremely high single doses, as daily, weekly, or monthly strategies are preferred over annual high doses 6
• If both vitamin D2 and D3 are available, supplementation with D3 is preferred for more reliable maintenance of serum levels 6

Monitoring Recommendations

• For those on supplementation, consider monitoring 25(OH)D levels to ensure target range is achieved without exceeding safety limits 6
• Slight reduction in supplementation dose may be warranted when levels approach 70-80 ng/mL 6

The evidence supporting vitamin D supplementation in COVID-19 is substantial though not definitive, with the most recent research suggesting potential benefits in reducing disease severity when deficiency is corrected 3. Given the safety, low cost, and potential benefits, maintaining adequate vitamin D levels is a prudent approach for individuals with COVID-19.