The 37th Parallel Edition [Mollie's Monday Obsessions v.121]

Populations living at a latitude higher than 37° north of the equator in the Northern Hemisphere are at the greatest risk of developing vitamin D deficiency.

Well, folks, it’s December, so if you’re in the US and living in the yellow section of the map below, it’s likely that the amount of sunlight you’re exposed to is insufficient in producing sufficient vitamin D levels throughout these upcoming winter months.

And if you live outside the US and find yourself in the gray section on the map below, the same rules apply. Your geographic location struggles to supply you with the amount of sunlight necessary to sustain optimal vitamin D levels (which is more of a hormone than a vitamin) until we reach warmer months.

So what does this have to do with sleep?

You can call it phototherapy, light therapy, or heliotherapy, it doesn’t matter. The point is that nothing will impact your circadian rhythm more than LIGHT.

Naturally, I’ve taken this idea to the extreme (standard ) and intentionally traveled to locations around the globe that fall below the 37th Parallel north to see what a steady supply of sunlight does for my sleep. ⁣

In sunny locations, below the 37th Parallel North, I’m averaging near or over 3 hours of deep sleep a night on the Oura Ring. When I return to NY, located well above the 37th parallel north, my sleep & health consistently tanks.⁣

***A couple of important callouts about this example: I’m showing deep sleep because so many of you ask about it. However, unfortunately, the sleep stage readouts on the hand & wrist-based wearables are unequivocally not there yet compared to a polysomnogram. Beyond this, there were a LOT of behavioral changes that occurred throughout all of these months. However, I’m clear that one of the most pressing changes was my increase in daily sunlight exposure.

So what do you do if you find yourself above the 37th Parallel North?

You will want to set up your days to be exposed to as much sunlight as possible, over as much of your skin's surface as possible. Which means that you don’t want to be bundled up so that only a small bit of your face is exposed to sunlight. I know that this can be challenging since it is often freezing in these locations (I’m originally from Maine, so I get it!). Ideally, you train to embrace the temperature from a cold thermogenesis perspective (also beneficial for your sleep!).

But for those of you who are NO for sunbathing in the cold, a lightbox can help. The Sperti Lightbox (no affiliation) is FDA cleared to generate Vitamin D. They also have units for those of us with psoriasis! You can see if your insurance will cover this expense.

Below is more information to ensure that you’re well-versed on this crucial topic that will not only impact your sleep but your health and mood.

37th Parallel Resources (How where you live is impacting your sleep & health!)


Resource: Article, Chromatherapy Light, SAD - Seasonal Affective Disorder


Resource: Article, Grass Roots Health, Sunshine Calendar


Resource: Article,, Effect of Latitude on Vitamin D Levels


Resource: Article, Inquiries Journal, Vitamin D Insufficiency Due to Insufficient Exposure to Sunlight and Related Pathology


Resource: Article, The role of Vitamin D in treatment of Chronic Insomnia with Melatonin (P5.320)


Resource: Book, Chasing the Sun: How the Science of Sunlight Shapes Our Bodies and Minds

Since the dawn of time, humans have worshipped the sun. And with good reason. Our biology is set up to work in partnership with it. From our sleep cycles to our immune systems and our mental health, access to sunlight is crucial for living a happy and fulfilling life. New research suggests that our sun exposure over a lifetime - even before we were born - may shape our risk of developing a range of different illnesses, from depression to diabetes.




️Resource: Podcast Episode, The Sleep Is A Skill Podcast, Dr. Jamie Zeitzer, Stanford U. & CMO Lumos Flux, Light Therapy & Sleep!

Resharing this episode because it is all about LIGHT! And there is a reason for that...strengthening your circadian rhythm is central to everything that we do at Sleep Is A Skill. It turns out that understanding and utilizing light is one of the most important ways to fulfill the goal of improving your sleep. Thankfully Dr. Jamie Zeitzer is a leader in this area and provides some excellent and practical takeaways that you can implement immediately.

Dr. Jamie Zeitzer’s Bio
A clinical champion and pioneer in the field of light therapy and circadian rhythms, Dr. Jamie Zeitzer, is a research professor at Stanford's Center for Sleep Sciences and Medicine, a member of Stanford Bio-X, and Chief Medical Officer of Lumos Health. He received his Ph.D. in neurobiology from Harvard in 1999 and has spent 25 years of his research career focusing on light, sleep, and circadian rhythms. Over the past few decades, Dr. Jamie Zeitzer has published over 123 papers in established journals and championed over five sleep-related clinical trials. His 6th trial, Bright Light as a Countermeasure for Circadian Desynchrony, is currently hiring.

In 2019, Dr. Jamie Zeitzer co-founded Lumos Health, a medical technology startup in the field of light therapy, providing research-oriented and clinically effective light therapy products combined with the latest nano-technology to create a personalized light environment for people looking to improve their sleep and wellbeing.

In this episode, we discuss:

  • Circadian rhythms
  • Impact of light on sleep
  • Lumos Flux (light therapy wearable glasses)
  • The science behind light therapy
  • Effects of irregular light exposure on health
  • How Jamie manages his light exposure
  • Can color-shifting your screen help you sleep easier?
  • Subjective sleep quality

As always, please send me your thoughts on this week’s obsession or your current fascinations.


P.S. Fed up with your sleep? Here are five ways to transform your sleep:

1. Subscribe to The Sleep Is A Skill Podcast
Get guidance from experts on all things sleep! We’ve got you covered from light, darkness, temperature, sound, meals (type & time), exercise, gadgets, etc.

2. Take our Free Sleep Assessment
Receive personalized feedback on where your sleep is and what it will take to turn it around.

3. Check out the Sleep Is A Skill Sleep Resource Recommendations
Inspired to transform your sleep but aren’t clear what sort of resources will help? Start here.

4. Book a 15 minute Call
We have something for everyone, no matter where you’re at with your sleep. Book a quick call to discuss what the next best steps are for you.

5. Get the Sleep Starter Stack
Oura Ring (no affiliation), Ooler from Chilipad, use this link and promo code CHILI22 for 22 percent off, a reliable pair of amber or red, blue blockers (clear lens will not cut it for the night) like TrueDarks, an HRV trainer like the Lief (use code: Sleepisaskill ), and a continuous glucose monitor (a common cause of wakeup and high body temperature). Skip the 50k person line with this link:


Naked and Unafraid to Exercise in Virtual Reality

Where Peloton or Mirror might offer ongoing streams of new classes, though, they are fixed physical platforms; VR fitness differentiates itself in letting users step outside the existing reality paradigm.

Naked and Unafraid to Exercise in Virtual Reality

Where Peloton or Mirror might offer ongoing streams of new classes, though, they are fixed physical platforms; VR fitness differentiates itself in letting users step outside the existing reality paradigm.

In this episode, we discuss:

Sleep Is A Skill Podcast


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