What is the Vitamin D dosing for a patient with Vitamin D deficiency?

From the Guidelines

For vitamin D deficiency, the recommended initial treatment is typically 50,000 IU of vitamin D2 or D3 taken orally once a week for 8 weeks, followed by a maintenance dose of 800-1000 IU daily, as recommended by recent guidelines 1. The goal of treatment is to bring serum 25(OH)D levels to 30 ng/mL or higher, which is essential for bone health and overall well-being.

• The initial loading dose of 50,000 IU weekly for 8 weeks is effective in quickly replenishing vitamin D stores, while the daily maintenance dose helps sustain adequate levels.
• For severe deficiency or malabsorption issues, higher doses may be needed, such as 50,000 IU twice weekly or even daily for several weeks, followed by the standard maintenance dose.
• It is crucial to recheck vitamin D levels after 8 weeks of treatment to ensure the deficiency has been corrected and adjust the maintenance dose as needed.
• Vitamin D supplementation should be accompanied by adequate calcium intake, either through diet or supplements, to support bone health, as recommended by the NCCN Bone Health in Cancer Care Task Force 1.
• Patients should also be advised on the importance of safe sun exposure and dietary sources of vitamin D to help maintain levels long-term. The choice between vitamin D2 and D3 may depend on patient preference and availability, but vitamin D3 is preferred due to its longer-lasting effects on serum 25(OH)D levels when given intermittently 1.

From the FDA Drug Label

Each tablet contains 50000 IU Vitamin D3 (Cholecalciferol) equivalent to 1.25 mg. Vitamin D3 50,000 IU is essential for absorption of calcium and necessary for healthy bones and a healthy immune system. The Vitamin D dosing for a patient with Vitamin D deficiency is 50,000 IU of Cholecalciferol, as indicated by the drug label 2.

• The dose is equivalent to 1.25 mg of Vitamin D3.
• This dose is necessary for the absorption of calcium and for maintaining healthy bones and a healthy immune system.

From the Research

Vitamin D Dosing for Deficiency

The dosing for Vitamin D deficiency can vary based on several factors, including the severity of the deficiency, age, and body mass index (BMI).

• The American Academy of Pediatrics recommends that infants and children receive at least 400 IU per day from diet and supplements 3.
• For adults with vitamin D deficiency, treatment may include oral ergocalciferol (vitamin D2) at 50,000 IU per week for eight weeks 3.
• After vitamin D levels normalize, maintenance dosages of cholecalciferol (vitamin D3) at 800 to 1,000 IU per day from dietary and supplemental sources are recommended 3.
• A study published in the European journal of endocrinology found that cholecalciferol in a cumulative dose of 100,000,150,000, and 200,000 IU increased mean serum 25-OHD(3) level by 29 nmol/l, 43 nmol/l, and 69 nmol/l respectively 4.
• The cholecalciferol loading dose required to reach the serum 25-OHD(3) target level of 75 nmol/l can be calculated as follows: dose (IU)=40x(75-serum 25-OHD(3))xbody weight 4.

High-Dose Vitamin D Supplementation

High-dose vitamin D supplementation has been studied in patients with increased risk of vitamin D deficiency.

• A study published in The Journal of steroid biochemistry and molecular biology found that long-term supplementation with vitamin D3 in doses ranging from 5000 to 50,000 IUs/day appears to be safe 5.
• A narrative review published in Nutrients found that daily vitamin D supplementation using higher than normal dosing (up to the upper limit value) and intermittent (once or twice per week) dosing were effective and safe for patients at high risk of vitamin D deficiency 6.
• The review suggested that daily doses of 7000 IU or intermittent doses of 30,000 IU/week should be considered for a prolonged time as prophylactic or maintenance doses, mainly in obese patients, patients with liver disease, and patients with malabsorption syndromes 6.

Predictive Equation for Vitamin D Replacement Dose

A predictive equation has been developed to guide vitamin D replacement dose in patients.

• The equation predicts the dose of vitamin D needed (in international units per day) to affect a given change in serum concentrations of 25-hydroxyvitamin D: Dose = [(8.52 - Desired change in serum 25-hydroxyvitamin D level) + (0.074 × Age) - (0.20 × BMI) + (1.74 × Albumin concentration) - (0.62 × Starting serum 25-hydroxyvitamin D concentration)]/(-0.002) 7.
• The study found that about 5000 IU vitamin D3/day is usually needed to correct deficiency, and the maintenance dose should be ≥2000 IU/day 7.