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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: 0.199s | 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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nonameiguess ◴[30 Jun 25 17:23 UTC] No.44425782[source]▶
Where is the data here? That article simply declares that there is a global epidemic of vitamin D deficiency and I followed the citation it gives to back that up, which is this: https://www.sciencedirect.com/science/article/pii/S000291652.... Except this citation is also not a study. It's an opinion piece that just declares people are vitamin D deficient without doing any measurements of how much vitamin D anyway has circulating in their blood. It appears to be a narrative review, not a study.

I'm not saying the claim is for sure wrong, but at some point, to make this claim, someone has to have actually measured vitamin D levels in some broadly representative sample of humans and you could post that instead of whatever came up first in Google Scholar when search for "vitamin D deficiency."

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1. agensaequivocum ◴[30 Jun 25 21:33 UTC] No.44428122[source]▶
This paper has a chart (figure 2) of the disease incidence prevention by serum vitamin D levels above the baseline of 25 ng/ml.

https://www.researchgate.net/publication/276034276_Vitamin_D...