How can I increase my vitamin D levels?

How to Increase Vitamin D Levels

The most effective way to increase vitamin D levels is to take a daily vitamin D3 supplement of 800-1,000 IU for mild deficiency, with higher doses needed for more severe deficiency, alongside sensible sun exposure and consuming vitamin D-rich foods. 1

Assessment and Testing

Before starting supplementation, consider these factors:

• Vitamin D levels are best checked at the end of winter or beginning of spring when levels are typically lowest 1
• High-risk individuals for vitamin D deficiency include:
  • People with severe obesity
  • Institutionalized or homebound individuals
  • Those with limited sun exposure (dark skin or clothing covering most of the body)
  • Older adults (≥65 years)
  • Patients with osteoporosis or high fracture risk 1

Supplementation Strategies

Dosing Based on Vitamin D Levels

Vitamin D Level	Supplementation Strategy
15-20 ng/mL	800-1,000 IU/day
5-15 ng/mL	50,000 IU weekly for 4-8 weeks, then maintenance
<5 ng/mL	Individualized treatment under close monitoring [1]

Population-Specific Dosing

• General population, dark-skinned individuals, adults ≥65 years: 800 IU/day 1
• Patients with obesity: 2-3 times higher doses (up to 7,000 IU daily) 1
• Patients with malabsorption: 50,000 IU 1-3 times weekly 1

Optimization Tips

1. Take vitamin D with your largest meal of the day

   • This improves absorption and can increase serum levels by approximately 50% 2
   • Fat in the meal helps with vitamin D absorption

2. Choose vitamin D3 (cholecalciferol) over vitamin D2 (ergocalciferol)

   • Vitamin D3 has higher bioefficacy 1, 3
   • For most people, D3 is the appropriate form for supplementation

3. Maintain consistent supplementation

   • Vitamin D is fat-soluble and builds up in the body over time
   • Daily dosing is generally preferred over large, infrequent doses 4
   • Single large doses of 300,000-500,000 IU should be avoided 4

Dietary Sources

While supplements are often necessary, include these natural sources:

• Oily fish (salmon, mackerel, sardines)
• Egg yolks
• Fortified foods (breakfast cereals, milk, yogurt) 5

Sun Exposure

Sensible sun exposure is an effective way to boost vitamin D levels:

• 5-30 minutes of sun exposure to face, arms, and legs twice weekly can help maintain adequate levels 4
• Sun exposure can provide vitamin D equivalent to 10,000 IU daily 6
• Balance sun exposure with skin cancer risk

Safety Considerations

• Vitamin D toxicity is rare and typically occurs with much higher doses (>10,000 IU daily for extended periods) 1, 6
• Long-term supplementation with doses ranging from 5,000 to 50,000 IU/day appears safe in monitored settings 7
• Serum 25-hydroxyvitamin D levels >150 ng/mL may indicate toxicity 1

Additional Considerations

• Ensure adequate calcium intake (1,000-1,500 mg daily) alongside vitamin D for optimal bone health 1
• Check vitamin D levels approximately 3 months after starting supplementation 1
• Maintenance therapy once sufficient levels are achieved: 800-1,000 IU daily 1, 4

Common Pitfalls to Avoid

• Taking vitamin D on an empty stomach reduces absorption 2
• Inconsistent supplementation leads to fluctuating levels
• Failing to address underlying causes of deficiency (e.g., malabsorption, medications)
• Not considering individual factors that affect vitamin D metabolism (obesity, age, skin tone)