44
Supplements · Guess & Rank
The Sunshine Test
Are you vitamin D deficient and don't know it?
Latitude, season, skin, sunscreen — estimate the status, then solve the dose.
3–4 min Core Science Score /100
Each scenario describes a real-life pattern. Will their vitamin D status trend up or down?
Educational only — not medical advice.
Companion Peer-Reviewed Article
Vitamin D Complete Guide
This interactive challenge was designed around peer-reviewed clinical research published on Health Secrets. Dive deeper into the biological mechanisms, human trial data, and practical implementation protocols.