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Show HN: I built a daily sunlight tracker

(www.lumehealth.io)
45 points vickipow | 1 comments | 26 Jun 25 23:28 UTC | HN request time: 0.391s | source

I kept trying to explain how important outdoor light is and how most people aren’t getting enough. Eventually I figured that showing is more effective than telling.

So we built a free app that uses your Apple Watch or iPhone to automatically track your light exposure throughout the day.

It tells you if you’re getting enough, shows you how consistent you are, and rewards habits that support hormone balance.

It's in beta on TestFlight, let me know what you think!

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Fraaaank ◴[30 Jun 25 13:04 UTC] No.44422805[source]▶
>how most people aren’t getting enough

What are you basing this on? What counts as 'enough'? And how are you tracking light exposure?

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snarf21 ◴[30 Jun 25 13:15 UTC] No.44422907[source]▶
There are countless studies that billions of people are Vitamin D deficient. Our bodies are designed to get most of that from the sun. Lots of people never even leave their house on a given day.

https://pmc.ncbi.nlm.nih.gov/articles/PMC3068797/

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aradox66 ◴[30 Jun 25 21:19 UTC] No.44427987[source]▶
I think this mostly has been debunked in the last 15 years, except in the unscientific health influencer space

https://pubmed.ncbi.nlm.nih.gov/39017376/

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1. agensaequivocum ◴[30 Jun 25 21:44 UTC] No.44428238[source]▶
Really the conclusion of that paper, that people are not vitamin D deficient, ought to be that people are sunlight deficient. This is why studies that involve supplementation of vitamin D frequently show no effect. Vitamin D is only one of many many ways in which light affects biology.

The paragraph near the end about babies needing fortified milk because breast milk is insufficient in vitamin D is laughable. It seems pretty obvious that babies are one of the most, if not the most, sunlight deficient demographics.