From the Guidelines
Vitamin D optimization is most effectively achieved through a combination of supplementation, dietary changes, and limited sun exposure.
Methods for Optimization
- Supplementation: Oral vitamin D, either vitamin D3 (cholecalciferol) or vitamin D2 (ergocalciferol), is commonly used to treat vitamin D deficiency 1.
- Dietary Changes: Increasing dietary vitamin D intake, particularly through consumption of oily fish, can help optimize vitamin D levels 1.
- Limited Sun Exposure: While UVB exposure can increase vitamin D levels, it is not generally recommended due to the increased risk of skin cancer 1.
Important Considerations
- Daily Dietary Vitamin D Intake: The Institute of Medicine recommends a daily dietary vitamin D intake of 600 IU in adults aged 18 to 70 years and 800 IU in adults older than 70 years 1.
- Testing and Supplementation: The decision to test for vitamin D deficiency and supplement should be made on a case-by-case basis, taking into account individual risk factors and health status 1.
From the Research
Methods for Optimizing Vitamin D Levels
The most effective methods for optimizing vitamin D (25-hydroxyvitamin D) levels include:
- Oral supplementation with vitamin D3 2, 3, 4, 5
- Taking vitamin D with the largest meal of the day to improve absorption 6
- Using different lipid delivery systems, such as olive oil or coconut oil, to enhance vitamin D absorption 4
- Considering intermittent (weekly or monthly) vitamin D supplementation as an alternative to daily supplementation 5
Key Findings
- Oral supplementation with 1,000 IU vitamin D3 daily significantly increased serum 25(OH)D levels in vitamin D-deficient participants after 3 months 2
- The dose-response to vitamin D supplementation decreased with increasing vitamin D status at baseline 3
- Taking vitamin D with the largest meal of the day improved absorption and resulted in a 56.7% increase in serum 25(OH)D levels 6
- Vitamin D fortification of lipid-containing foods may be used in lieu of supplementation when supplement adherence is low or for individuals with dysphagia 4
- Weekly supplementation with a total of 600,000 IU vitamin D supplementation during 3 months had the best efficacy in elevating 25(OH)D concentration 5
Considerations
- The efficacy of intermittent vitamin D supplementation was similar to daily supplementation 5
- The frequency and dosage of intermittent vitamin D supplements should be recommended to reach the optimal 25(OH)D level 5
- The recommended dietary intake of 15 microg is adequate to maintain the S-25-OHD concentration around 40-55 nmol/L during winter, but higher vitamin D intakes may be needed for optimal levels 3