From the Guidelines
For a vitamin D level of 23.9 ng/mL, the recommended supplementation regimen is 2,000-4,000 IU of vitamin D3 daily for 8-12 weeks, followed by a maintenance dose of 1,000-2,000 IU daily. This recommendation is based on the most recent and highest quality study available, which suggests that vitamin D3 is more effective in raising 25(OH)D concentrations and maintaining those levels for a longer time when longer dosing intervals are employed 1.
Key Considerations
- Start with the higher dose (4,000 IU) if your level is closer to deficiency or if you have symptoms.
- Take vitamin D supplements with a meal containing some fat to improve absorption.
- After the initial treatment period, recheck your vitamin D level to ensure it has increased to the optimal range of 30-50 ng/mL.
- If you're still below target, continue the higher dose for another 8-12 weeks.
Importance of Vitamin D
Vitamin D is essential for calcium absorption, bone health, immune function, and may help prevent various chronic diseases. The body can produce vitamin D when skin is exposed to sunlight, but many people don't get enough sun exposure or have factors that limit vitamin D production, making supplementation necessary to correct insufficient levels. According to the NCCN task force report, 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 1.
Choosing the Right Supplement
Vitamin D3 is preferred over vitamin D2 due to its longer duration of action and better maintenance of serum 25(OH)D levels 1. However, for strict vegetarians or those with religious preferences, vitamin D2 may be a suitable alternative. It's also important to note that the need for calcium supplementation depends on the patient's diet, and strict vegetarians may require additional calcium supplements.
From the Research
Vitamin D Supplementation Regimen
To address a vitamin D level of 23.9 ng/mL, which is considered insufficient according to the definition provided by 2, supplementation is necessary. The goal of supplementation is to normalize vitamin D levels, relieve symptoms, and decrease the risk of fractures, falls, and other adverse health outcomes.
Recommended Dosage
- The American Academy of Pediatrics recommends at least 400 IU per day for infants and children, but for adults, especially those with insufficient levels, a higher dose is recommended 2.
- Evidence suggests that vitamin D supplementation of at least 700 to 800 IU per day reduces fracture and fall rates in adults 2, 3.
- For individuals with vitamin D deficiency, treatment may include oral ergocalciferol (vitamin D2) at 50,000 IU per week for eight weeks, followed by maintenance dosages of cholecalciferol (vitamin D3) at 800 to 1,000 IU per day from dietary and supplemental sources 2.
- Other studies recommend a daily dose of 1,000-1,200 mg calcium and 800 IU vitamin D for elderly or institutionalized people, patients with established osteoporosis, and individuals on glucocorticoids 4, 5.
Considerations
- It's important to note that combined calcium and vitamin D supplementation may be associated with cardiovascular risks, although the evidence is not conclusive, and more research is needed 4.
- The optimal dosing schedule for vitamin D supplementation is unknown and requires further study, but more frequent, lower doses are preferred over annual high-dose administration 4.
- Patient compliance is crucial for the effectiveness of calcium and vitamin D supplementation, and formulations like calcium citrate may help optimize compliance by minimizing side effects 5.