From the Guidelines
Vitamin D 50,000 units once a week is a recommended high-dose supplementation regimen for patients with vitamin D deficiency, as stated in the most recent and highest quality study 1. This dosage is usually taken for 8 weeks to rapidly correct severe deficiency, after which a lower maintenance dose is often recommended. The weekly dosing schedule is convenient and improves adherence compared to daily dosing. Some key points to consider when taking vitamin D supplements include:
- Vitamin D is essential for calcium absorption, bone health, immune function, and other bodily processes.
- The body can store vitamin D in fat tissues, which allows for effective weekly dosing.
- After completing the prescribed course, your doctor will likely recheck your vitamin D levels and may transition you to a lower maintenance dose (typically 1,500-2,000 IU daily) as recommended by 1.
- Taking vitamin D with food containing some fat improves absorption.
- Excessive vitamin D supplementation without monitoring can lead to toxicity, so follow your healthcare provider's instructions carefully. It's also important to note that vitamin D3 is preferred over vitamin D2 for supplementation, as it maintains serum 25(OH)D levels for a longer period, as mentioned in 1. However, the most recent study 1 provides the most up-to-date guidance on vitamin D supplementation, and its recommendations should be prioritized.
From the Research
Vitamin D Supplementation
- The use of vitamin D supplements has increased substantially over the last decade, with epidemiologic evidence linking vitamin D deficiency to various illnesses 2.
- The Institute of Medicine recommends vitamin D supplementation for indications other than musculoskeletal health, but the evidence is not adequately supported 2.
- The recommended dietary allowance of vitamin D is 400-800 IU per day for adults, with a goal of achieving a serum 25-hydroxyvitamin D concentration of at least 20 ng/ml 3.
Dosage and Administration
- Vitamin D in doses of 800-5000 IU/day can improve musculoskeletal health, reducing the rate of fractures and falls in older adults 2.
- A cumulative dose of at least 600,000 IU administered over several weeks may be necessary to replenish vitamin D stores in patients with documented deficiency 2.
- Single large doses of 300,000-500,000 IU should be avoided, and vitamin D supplementation should not be offered routinely to other patient populations 2.
Specific Dosage of 50,000 Units Once a Week
- There is no specific evidence to support the use of 50,000 units of vitamin D once a week, but some studies suggest that high-dose vitamin D supplementation may be necessary for certain populations, such as those with inflammatory bowel disease or prior gastric bypass 3.
- The European Society of Clinical and Economical Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) working group recommends 1000 IU daily for patients at increased risk of vitamin D deficiency, but also addresses the identification of patients possibly benefitting from a vitamin D loading dose 4.
Health Effects of Vitamin D Supplementation
- Vitamin D supplementation can prevent and cure nutritional rickets in infants and children, but the causal link between vitamin D and many extra-skeletal outcomes remains unclear 5.
- Most guidelines recommend serum 25OHD concentrations of >50 nmol/l for optimal bone health in older adults, but supplementation of vitamin D-replete individuals does not provide demonstrable health benefits 5.