What is Vitamin D?
Vitamin D is a fat-soluble vitamin. Skin makes it when UVB light hits it. Supplements come as D2 or D3.
What it does for skin
The NIH fact sheet says experts do not believe excessive sun exposure results in vitamin D toxicity. Toxicity almost always comes from excessive supplement intake.
The NIH fact sheet warns that frequent tanning-bed use can push 25(OH)D levels well above 150 to 200 ng/mL.
We found no controlled trial in the NIH sources reviewed showing that vitamin D supplements reduce wrinkles or improve skin tone.
What the research shows
Three meta-analyses of clinical trials found that supplementation did not affect cancer incidence, but reduced total cancer mortality by 12% to 13%.
In the VITAL trial, breast, prostate and colorectal cancer rates did not differ significantly between the vitamin D and placebo groups.
The NIH fact sheet says clinical trials show vitamin D supplementation does not reduce cardiovascular disease risk.
Forms, amounts and limits
The NIH recommended amount is 600 IU (15 mcg) a day for adults aged 19 to 70, and 800 IU (20 mcg) a day for people over 70.
The NIH tolerable upper limit is 4,000 IU (100 mcg) a day.
Safety
Do not exceed the 4,000 IU upper limit without medical advice.
Talk to a doctor or pharmacist before starting any supplement, especially if you are pregnant, breastfeeding, have a medical condition or take medicines.
Questions
Should I take vitamin D in winter?
It depends on your sun exposure and your levels. Ask a clinician whether testing is right for you.
Will vitamin D improve my skin?
The NIH sources we reviewed do not show that. Supplements are for preventing deficiency, not for anti-aging.
Sources
General information, not medical advice. Vanu Health does not sell this supplement. Read our terms.