From the Guidelines
You should take vitamin D supplements to raise your levels, as 13 ng/mL indicates vitamin D deficiency, with a goal to achieve a level of 30 ng/mL or higher for optimal bone health. According to the NCCN task force report 1, vitamin D should ideally be supplemented in amounts sufficient to bring serum 25(OH) D levels to 30 ng/ml (75 nmol/L) or higher. A common regimen for patients with serum 25(OH) D levels below 30 ng/mL is prescription vitamin D (ergocalciferol) 50,000 IU weekly for 8 weeks, followed by a recheck of the serum 25(OH) D level, with subsequent dosing based on the results 1. Some key points to consider when taking vitamin D supplements include:
- Taking supplements with a meal containing some fat to improve absorption
- Including vitamin D-rich foods in your diet such as fatty fish, fortified dairy products, and eggs
- Trying to get 15-30 minutes of sunlight exposure several times per week
- Retesting your vitamin D levels after 3 months of supplementation to ensure they're improving toward the target range of 30-50 ng/mL It's also important to note that vitamin D toxicity is uncommon but may occur with daily doses of more than 50,000 IU per day that produce 25(OH) D levels larger than 150 ng/mL 1.
From the Research
Vitamin D Levels and Supplementation
Your vitamin D level is 13 ng/mL, which is considered low. According to the study 2, a minimum 25(OH)D level of 32 ng/mL is necessary for optimal protection from fracture and intestinal absorption of calcium.
Increasing Vitamin D Levels
To increase your vitamin D levels, you may consider supplementation. The study 3 suggests that increasing the recommended daily allowance of vitamin D to 800 to 1,000 IU per day may be beneficial for most age groups. However, the study 4 found that vitamin D3 increased total and free 25D levels to a greater extent than vitamin D2.
Comparison of Vitamin D2 and D3
The studies 4 and 5 compared the effects of vitamin D2 and D3 supplementation. The results showed that vitamin D3 is more effective in increasing total 25D levels than vitamin D2. Additionally, vitamin D2 supplementation was associated with a decrease in 25(OH)D3 levels 5.
Calcium and Vitamin D Supplementation
The study 6 found that daily supplementation with both vitamin D and calcium was associated with a reduced risk of fracture. The recommended daily doses of vitamin D and calcium were 400-800 IU and 1000-1200 mg, respectively.
Key Points to Consider
- Your vitamin D level is low, and supplementation may be necessary.
- Vitamin D3 may be more effective than vitamin D2 in increasing total 25D levels.
- Calcium and vitamin D supplementation may be associated with a reduced risk of fracture.
- The recommended daily doses of vitamin D and calcium are 400-800 IU and 1000-1200 mg, respectively.