What dose of vitamin D (Vit D) should be administered to a patient with vitamin D deficiency?

From the Guidelines

For patients with low vitamin D levels, I recommend starting with 50,000 IU of vitamin D2 or D3 once weekly for 8 weeks, followed by maintenance therapy of 800-1000 IU daily, as suggested by the NCCN Bone Health in Cancer Care Task Force 1. The goal of vitamin D supplementation is to achieve and maintain serum 25-hydroxyvitamin D levels above 30 ng/mL, which is ideal for bone health 1.

• The initial loading dose of 50,000 IU weekly for 8 weeks is intended to rapidly increase vitamin D levels in patients with severe deficiency.
• After completing the initial treatment, recheck vitamin D levels and adjust the maintenance dose accordingly, taking into account individual patient needs and response to therapy.
• It is essential to monitor patients periodically, especially those on long-term therapy, to ensure levels remain in the appropriate range without reaching toxicity, which can occur with daily doses of more than 50,000 IU per day 1.
• The choice between vitamin D2 and D3 may not be critical, as both forms can be effective in raising 25(OH) D concentrations, although vitamin D3 may be more effective in maintaining those levels for a longer time when longer dosing intervals are employed 1.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION THE RANGE BETWEEN THERAPEUTIC AND TOXIC DOSES IS NARROW. Vitamin D Resistant Rickets: 12,000 to 500,000 IU units daily. Hypoparathyroidism: 50,000 to 200,000 IU units daily concomitantly with calcium lactate 4 g, six times per day. DOSAGE MUST BE INDIVIDUALIZED UNDER CLOSE MEDICAL SUPERVISION.

The recommended dose of vitamin D for a patient with low vitamin D levels is not explicitly stated in the provided drug labels for treatment of low vitamin D. However, for Vitamin D Resistant Rickets and Hypoparathyroidism, the doses are:

• 12,000 to 500,000 IU units daily
• 50,000 to 200,000 IU units daily, respectively 2. For a dietary supplement, the direction is to take one 50,000 IU capsule each week, or as directed by a physician 3. DOSAGE MUST BE INDIVIDUALIZED UNDER CLOSE MEDICAL SUPERVISION.

From the Research

Vitamin D Dosage for Patients with Low Vitamin D Levels

The recommended dosage of vitamin D for patients with low levels can vary depending on the severity of the deficiency and the individual's overall health.

• For prevention, the American Academy of Pediatrics recommends at least 400 IU per day from diet and supplements for infants and children 4.
• For adults, evidence shows that vitamin D supplementation of at least 700 to 800 IU per day reduces fracture and fall rates 4.
• In persons with vitamin D deficiency, treatment may include oral ergocalciferol (vitamin D2) at 50,000 IU per week for eight weeks 4.
• After vitamin D levels normalize, experts recommend maintenance dosages of cholecalciferol (vitamin D3) at 800 to 1,000 IU per day from dietary and supplemental sources 4.
• Other studies have shown that long-term supplementation with vitamin D3 in doses ranging from 5000 to 50,000 IUs/day appears to be safe 5.
• A study comparing vitamin D2 and vitamin D3 found that 1000 IU of vitamin D2 daily was as effective as 1000 IU vitamin D3 in maintaining serum 25-hydroxyvitamin D levels 6.
• However, another study suggested that vitamin D3 may be more effective than vitamin D2 in increasing serum 25(OH)D levels 7.
• A retrospective evaluation of prescription ergocalciferol dosing for vitamin D repletion found that an ergocalciferol regimen of 50,000-100,000 IU/week could be considered as a starting point for vitamin D repletion 8.

Key Considerations

• The choice between vitamin D2 and vitamin D3 may depend on individual patient factors and the severity of the deficiency.
• The dosage and duration of treatment should be tailored to the individual patient's needs and response to treatment.
• Regular monitoring of vitamin D levels is necessary to ensure that the treatment is effective and to adjust the dosage as needed.