Education only · provider review required
Vitamin D · Common deficiency, overstated cure-all
Test, correct if low, and ignore the megadose marketing.
Medically reviewed by Bernard Garcia, MD
What it is
Vitamin D deficiency is common, especially with limited sun exposure, darker skin or obesity, and correcting it matters for bone health. Large trials of supplementation in people who are not deficient (VITAL and others) found no benefit for cancer, cardiovascular disease or most other outcomes.
How it works
Vitamin D is made in skin and obtained from few foods; a 25-OH vitamin D blood test measures status. High-dose injections ("D3 shots") are used in some clinics; oral supplementation is the standard and toxicity from megadoses is real.
Research status
| Research area | Status |
|---|---|
| Deficiency correction | Established |
| Bone health | Established (with calcium) |
| Cancer / cardiovascular prevention in replete people | No benefit in large trials |
| Injectable D3 "shots" | Not FDA-approved in US |
Status reflects published research context only and is not a statement of safety, efficacy, or suitability for any person.
Is it legal?
Oral vitamin D is a supplement or prescription (high-dose); injectable vitamin D is not FDA-approved in the US. This is a general note, not medical advice.
Frequently asked questions
Should everyone take vitamin D?
Test first. Many people benefit from modest supplementation; megadoses do not add benefit and can harm.
Why is it on this site?
It is sold alongside peptides and hormones as "longevity" — and it is one of the few things here that a simple test settles.
Does Vitrex sell it?
No.
Next step
Next step: a 3-minute confidential intake, reviewed by a licensed provider. No treatment is promised or implied.
Free · about 10 minutes · reviewed by a licensed physician
General education · Not medical advice · Provider approval required