Vitamin D3
Cholecalciferol is converted in the liver and kidney to calcitriol, the active hormone regulating calcium absorption, bone metabolism, and immune signaling.
Medically reviewed by Dr. Jonathan Snipes, MD. Last reviewed May 6, 2026.
What It Is
An injectable form of vitamin D3 (cholecalciferol) at 50,000 IU/mL. Self-administered intramuscular, typically dosed weekly to monthly per labs.
How It Works
Injected D3 is hydroxylated to 25-hydroxyvitamin D and then to active calcitriol, supporting calcium and phosphate homeostasis, bone mineralization, and immune function. Injection helps patients with malabsorption or persistent deficiency on oral D3.
Who It's For
Patients with documented vitamin D deficiency or malabsorption who have not responded to oral supplementation. Dosing guided by 25-OH vitamin D labs.
Who Should Avoid It
Hypercalcemia, hypervitaminosis D, or sarcoidosis-related calcium dysregulation. Dose by lab values; do not stack multiple high-dose D sources. Flag for provider review.
Protocol & Pricing
OBP Pharmacy Price
$55/30ml
You pay pharmacy price. No markup.
Starting Dose
50,000 IU (1mL) once monthly
Form
Injectable vial (30mL, 50,000 IU/mL cholecalciferol)
Dosing Protocol
50,000 IU (1mL at 50,000 IU/mL) intramuscular once monthly, or per provider based on 25-OH vitamin D labs. Single 30mL vial ($55). Do not exceed provider-directed dosing.
Beyond Use Date
90 Days from compounding (USP <797>)
Optimal Balance Pharmacy assigns this date and prints it on your vial label. Always follow the label. Once a multi-dose vial is punctured, the in-use date on the label is shorter than the compounding date shown here.
Stacking Guide
Stacks Well With
Related Peptides
How to get Vitamin D3 prescribed online
Vitamin D3 is available by prescription through a licensed telehealth visit and dispensed for human use by a named 503A pharmacy. That is what separates it from research-use-only vials sold without a prescription. There is no subscription and no membership, just a one-time visit fee.
- 1
Complete a $39 medical visit. Answer a short intake about your health history and your goals for Vitamin D3. The $39 fee is the only charge RxPepsDirect collects, paid once, not a recurring subscription.
- 2
A licensed provider reviews it. A US-licensed nurse practitioner or physician reviews your intake and, if Vitamin D3 is appropriate for you, writes a patient-specific prescription. The starting dose is typically 50,000 IU (1mL) once monthly.
- 3
The pharmacy compounds and ships it. Optimal Balance Pharmacy, a 503A pharmacy in Texas, compounds Vitamin D3 and ships it pre-reconstituted by FedEx overnight in a reusable cooled case. Your fill is Injectable vial (30mL, 50,000 IU/mL cholecalciferol), and you pay the pharmacy $55/30ml at wholesale, with no clinic markup, plus a $15 flat FedEx overnight shipping fee charged by the pharmacy.
RxPepsDirect prescribes Vitamin D3 in the 29 jurisdictions its medical team is licensed in. Start a $39 visit or browse the full Vitamins & Injectables range. Comparing services first? See how RxPepsDirect stacks up against seven other providers in our best telehealth for compounded peptides comparison.
Common questions about Vitamin D3
- What is Vitamin D3?
- An injectable form of vitamin D3 (cholecalciferol) at 50,000 IU/mL. Self-administered intramuscular, typically dosed weekly to monthly per labs.
- How does Vitamin D3 work?
- Injected D3 is hydroxylated to 25-hydroxyvitamin D and then to active calcitriol, supporting calcium and phosphate homeostasis, bone mineralization, and immune function. Injection helps patients with malabsorption or persistent deficiency on oral D3.
- Who is Vitamin D3 for?
- Patients with documented vitamin D deficiency or malabsorption who have not responded to oral supplementation. Dosing guided by 25-OH vitamin D labs.
- How much does Vitamin D3 cost?
- Vitamin D3 costs $55/30ml from Optimal Balance Pharmacy at wholesale, with a flat $39 medical visit fee from RxPepsDirect. The form is Injectable vial (30mL, 50,000 IU/mL cholecalciferol).
- What is the Beyond Use Date for Vitamin D3?
- Optimal Balance Pharmacy assigns the Beyond Use Date for Vitamin D3 and prints it on the vial label. The listed figure is 90 Days from compounding (USP <797>). Always follow the date on your own label, and note that once a multi-dose vial is punctured, the in-use date on the label is shorter than the compounding BUD.