Vitamin D-3 1250 mcg (50,000 IU) Weekly — 50 Softgels — Bone & Immune Support*
High-potency Vitamin D3 (cholecalciferol) to support bone health, calcium absorption, and immune function. This 50,000 IU softgel is intended for physician-directed use in clinically significant deficiency. Produced in FDA-registered, GMP-certified facilities and 3rd-party tested for identity, potency & purity. Use only under medical supervision due to high dosage.*
Research-Driven & Verified Product.
Explore the clinical research, ingredient science, and global evidence supporting this product below.
Research Promise: At LifeSource Vitamins, our commitment is rooted in research and results. Every benefit below is supported by human clinical studies indexed in the National Institutes of Health (NIH) via PubMed, with full texts available in the National Library of Medicine (NLM) PubMed Central (PMC) when available. In addition, we reference reviews from leading health organizations and insights from top global universities to ensure our guidance aligns with credible science.*
Clinically Studied Benefits
✓ Supports calcium absorption & bone strength — RCTs show improved absorption.
NIH/PubMed — Shapses, 2013
✓ Helps prevent rickets & osteomalacia in deficiency — Corrects mineralization defects.
NIH/PubMed — Griffin, 2021
✓ Supports immune function — Meta-analysis found modest protective effect against ARIs with daily dosing.
NIH/PubMed — Jolliffe, 2021
✓ Supports muscle strength & balance — Improvements in older adults.
NIH/PubMed — Qi, 2024
✓ Supports cardiovascular function — Subgroup trials suggest BP regulation.
NIH/PubMed — Zhang, 2020
✓ Supports mood balance — Meta-analysis shows small improvements in depressive symptoms.
NIH/PubMed — Wang, 2024
✓ Signals for lower cancer mortality — Reduced total cancer mortality in meta-analysis.
NIH/PubMed — Keum, 2019
✓ Vitamin D3 & bone density — Minimal effect without deficiency.
NIH/PubMed — Reid, 2014
✓ Vitamin D3 high-dose daily caution — 4000–10,000 IU/day did not improve BMD, ↑ hypercalciuria.
NIH/PubMed — Burt, 2019
Additional / Promising Evidence
✓ Vitamin D3 & insulin sensitivity (prediabetes) — mixed RCT outcomes.
NIH/PubMed — Pittas, 2019
✓ Vitamin D3 & blood pressure — generally null, possible small subgroup benefit.
NIH/PubMed — Zhang, 2020
✓ Vitamin D3 & athletic performance — strength gains in deficiency cases.
NIH/PubMed — Han, 2024
University-Led & Academic Studies
✓ Supports calcium absorption & bone strength — RCTs show improved absorption.
NIH/PubMed — Shapses, 2013
✓ Helps prevent rickets & osteomalacia in deficiency — Corrects mineralization defects.
NIH/PubMed — Griffin, 2021
Global Evidence & Reviews
✓ NIH ODS — Vitamin D — Health-professional fact sheet on roles, deficiency, supplementation, and safety.
NIH/ODS — Vitamin D
✓ NCCIH — Vitamin D — Overview of uses, evidence, and safety considerations.
NIH/NCCIH — Vitamin D
We monitor research from leading institutions —
Harvard, Johns Hopkins, Mayo Clinic, Cleveland Clinic, Cambridge, Oxford, Stanford, Yale, Tufts, University of Florida, Oregon State University – Linus Pauling Institute, Columbia, Cornell, Ohio State — to align with credible science.*
Key Ingredients
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Vitamin D3 (cholecalciferol) — Supports calcium absorption, bone strength, immune function, muscle health, and mood; benefits strongest when levels are low. (NIH/ODS — Vitamin D)
Brief Benefit Bullets
- Supports bone health & calcium absorption*
- Helps prevent rickets/osteomalacia in deficiency*
- May reduce falls in older adults (daily 800–1000 IU)*
- Supports muscle function in deficiency*
- Cancer: signals for lower advanced/fatal cases & mortality*
- Immune/ARI evidence mixed*
- Physician-directed high-dose repletion only*
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3rd-party lab tested for identity, potency & purity
Suggested Use
See product label for full instructions, or as directed by your healthcare professional. Do not exceed recommended dose. If pregnant, nursing, taking medications, or have a medical condition, consult your physician. Important: This high-dose product (50,000 IU) is for short-term repletion under medical supervision and is not for unsupervised daily use.*
Product Specifications
• Serving Size — 1 softgel
• Servings Per Container — 50
• Form — Softgels
• Free From — Non-GMO, gluten-free, no artificial colors*
• Quality — Third-party tested for identity, potency & purity
LifeSource Vitamins — Proudly American — Since 1992
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
Vitamin D3 50,000 IU weekly softgels — physician-guided repletion for deficiency; supports calcium absorption, bone & muscle health; 3rd-party tested. Clinically Studied Ingredients — NIH/PubMed!*
