Evidence-based articles about vitamin D, sun exposure, and health optimization.
54 articles
Spending most of the day indoors can quietly drain vitamin D levels. Here's what the evidence shows about indoor work, sun exposure gaps, and practical ways to close them.
Overcast skies don't zero out vitamin D synthesis, but they cut it sharply. Here's what the science says about clouds, weather, and how much UVB actually reaches your skin.
Children's vitamin D needs differ sharply from adults — by age, growth stage, and latitude. Here's what clinical evidence shows about deficiency risk, sun exposure, and supplementation in kids.
Most foods contain far less vitamin D than labels suggest. Here's what the evidence says about fatty fish, fortified products, and mushrooms — and when food alone falls short.
Sun exposure raises vitamin D but also UV damage risk. Here's what the clinical evidence says about balancing smart sun time against skin cancer — without fear or false reassurance.
Low vitamin D levels appear consistently in people with insulin resistance and type 2 diabetes. Here's what trials and large cohort studies say about the link — and what remains contested.
Taking D3 alone may push calcium where it shouldn't go. Here's what the evidence says about combining D3 with K2 (MK-7) for safe, effective supplementation.
Crossing a time zone or hemisphere resets your vitamin D sun window entirely. Here's how UV index shifts when you travel — and how to recalibrate your sun exposure.
Body fat sequesters vitamin D, which helps explain why people with obesity consistently test lower — even with similar sun exposure. Here's what the research actually shows.
UV index, skin tone, season, and latitude all determine whether your outdoor time actually raises vitamin D levels. Here's how to know if your sun exposure is working.