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 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 39 leading health organizations and insights from 20 top global universities to ensure our guidance aligns with credible science.*
Clinically Studied Benefits (with research)
• Vitamin D3 supports calcium absorption* — RCTs show improved absorption. (NIH/PMC — Shapses SA, 2013)
• Vitamin D3 prevents rickets/osteomalacia in deficiency* — Corrects mineralization defects. (NIH/PMC — Griffin G, 2021)
• Vitamin D3 may reduce falls in older adults* — Benefit at daily 800–1000 IU. (NIH/PubMed — Kong SH, 2022; NIH/PubMed — Wei FL, 2022)
• Vitamin D3 supports muscle strength* — Meta-analysis shows improvements. (NIH/PMC — Qi P, 2024)
• Vitamin D3 & respiratory infections* — Mixed; daily dosing modest, updated analyses null. (NIH/PubMed — Jolliffe DA, 2021; NIH/PubMed — Jolliffe DA, 2024)
• Vitamin D3 & cancer outcomes* — No effect on incidence, but ↓ advanced/fatal cases. (NIH/PubMed — Manson JAE, 2019; NIH/PubMed — Chandler PD, 2020)
• Vitamin D3 may reduce cancer mortality* — Meta-analysis signal for ↓ mortality. (NIH/PMC — Keum N, 2019)
• Vitamin D3 & bone density* — Minimal effect without deficiency. (NIH/PubMed — Reid IR, 2014; NIH/PubMed — Reid IR, 2017)
• Vitamin D3 high-dose daily caution* — 4000–10,000 IU/day did not improve BMD, ↑ hypercalciuria. (NIH/PubMed — Burt LA, 2019)
• Vitamin D3 & depression (mixed)* — Small improvements; variable by baseline. (NIH/PubMed — Wang R, 2024)
Additional Studies Showing Promising Benefits*
• Vitamin D3 & insulin sensitivity (prediabetes) — mixed RCT outcomes. (NIH/PubMed — Pittas AG, 2019)
• Vitamin D3 & blood pressure — generally null, possible small subgroup benefit. (NIH/PubMed — Zhang D, 2020)
• Vitamin D3 & athletic performance — strength gains in deficiency cases. (NIH/PubMed — Han Q, 2024)
Global Evidence & Authoritative Reviews*
• NIH ODS — Vitamin D Fact Sheet (NIH/ODS)
• NCCIH — Vitamins & Minerals overview (NCCIH)
• Mayo Clinic — Vitamin D overview (Mayo Clinic)
• Cleveland Clinic — Deficiency explainer (Cleveland Clinic)
• NCI — Vitamin D & Cancer Q&A (NCI)
We monitor research from the world’s leading institutions — including Harvard, Johns Hopkins, Mayo Clinic, Cleveland Clinic, Cambridge University, Oxford, Stanford, Yale, MIT, the University of Florida, Oregon State University – Linus Pauling Institute, Tufts, Boston University, Cornell, Columbia, and Ohio State — to ensure our guidance remains aligned with the highest standards of credible science.*
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*
• 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
Perfect For
• Adults with clinically confirmed deficiency (physician-directed)*
• Those needing supervised repletion to support bone & muscle health*
• Individuals seeking immune support with clinician guidance*
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!*
