From the Guidelines
For vitamin D deficiency, daily supplementation is generally better than weekly high-dose therapy of 50,000 IU. According to the NCCN task force report 1, daily dosing of vitamin D is more effective in maintaining consistent 25(OH) D levels, and vitamin D3 could be more effective in raising 25(OH) D concentrations and maintaining those levels for a longer time when longer dosing intervals are employed.
Some key points to consider when supplementing with vitamin D include:
- The goal is to bring serum 25(OH) D levels to 30 ng/ml (75 nmol/L) or higher for bone health 1
- Vitamin D3 is available in supplements and could be more effective than vitamin D2 in raising 25(OH) D concentrations 1
- Daily supplementation with 1000 IU of vitamin D2 or D3 per day can be an alternative for patients with 25(OH) D levels between 20 and 30 ng/mL 1
- 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
In terms of specific recommendations, taking 800 to 1000 IU of vitamin D daily is recommended for most adults with deficiency 1. It's also important to note that many patients need more than the recommended amount and should be repleted based on serum 25(OH) D level 1. Regular blood tests every 3-6 months are important to monitor your levels and adjust dosing as needed. Combining supplementation with brief sun exposure and consuming vitamin D-rich foods like fatty fish, egg yolks, and fortified dairy can help maintain healthy levels.
From the Research
Vitamin D Deficiency and Supplementation
- Vitamin D deficiency is a public health problem with high prevalence and adverse clinical consequences, including musculoskeletal health and extraskeletal diseases 2, 3.
- Daily vitamin D supplementation is often recommended, with a suggested daily dose of 2000 international units (IU) (50 µg) of vitamin D3 to prevent and treat vitamin D deficiency 2.
- A daily vitamin D supplementation with 2000 IU (50 µg) may be considered a simple, effective, and safe dosage to prevent and treat vitamin D deficiency in the adult general population 2.
Comparison of Daily and Weekly Supplementation
- There is evidence to suggest that daily vitamin D supplementation may be more effective than weekly or single large-dose supplementation in maintaining serum 25(OH)D concentrations above 50 nmol/L (20 ng/mL) 4, 5.
- However, single large doses of vitamin D, such as 50,000 IU weekly, may be effective in increasing serum 25(OH)D concentrations in vitamin D-deficient populations, but may not be sufficient to maintain optimal vitamin D status 4.
- Vitamin D doses >500,000 IU should be used judiciously to minimize adverse events, and daily supplementation may be a safer and more effective approach 4.
Safety and Efficacy Considerations
- Vitamin D supplementation is generally considered safe, but overdosing can lead to intoxication with severe health consequences 3, 6.
- The optimal vitamin D dose and status are still debated, and large interventional studies have been unable to show a clear benefit in mostly vitamin D-replete populations 5.
- A 25(OH)D level of >50 nmol/L or 20 ng/ml is the primary treatment goal, although some data suggest a benefit for a higher threshold 5.