Hi there,

I had some questions about living a nocturnal schedule. I'm a 35 year old male who, for the last 12 years old patientor so, has (by choice and working for myself) lived mostly a nocturnal schedule. That is to say I usually wake up at 3 or 4 in the afternoon and go to bed at 7 or 8 in the morning. I tend to sleep fairly well most nights (I aim for 6-7 hours a night; occasionally I get 8+). While I am obese, I do exercise regularly, walk lots, and try to eat healthy. I don't smoke, but I do drink (I try to keep it decently moderate since my 20's). I also take several supplements (multivitamin, fish oil, Q10, garlic, fruits/veggie powder as well as the real things, etc.).

Several studies have seemed to indicate people who go against their circadian rhythms have ~3X the cancer risk, more cardiovascular risk, higher chance of metabolic problems, etc. This has worried me, and I want to see what I can do to reduce or eliminate the risk. I should say a lot of these studies, but not all (some show increased risk even with a fixed schedule), deal with rotating schedules (ie. night shift two weeks, day shift the next two weeks), which ISN'T a regular problem for me - my schedule stays fairly consistent (a few exceptions within a year, but not that many).

Additionally, last year when I visited my doctor, I checked Vitamin D levels and have increased Vitamin D along with her recommendation (in addition to getting some sunshine in the afternoon hours). I do sleep with the blinds closed, but it's not a completely dark room. That doesn't seem to bother me, though. I've considered taking low dose melatonin nightly, but have yet to discuss it with my doctor.

I could potentially shift to a day schedule, but I really don't want to if I can avoid it and still be healthy maintaining my nights schedule.

My questions:
1.) I've always kind of gravitated toward this schedule. Is it possible for this to be someone's "natural" rhythm?
2.) Is there any reason, aside from Vitamin D and melatonin, that people who are awake at night are prone to all these risks, or can supplementation of D and melatonin potentially even things out with the general population?
3.) Is it okay for my room to NOT be pitch black when I sleep?
4.) Is a fixed nights schedule any better than someone who's constantly rotating?
5.) Any other suggestions to minimize risk?
6.) In your opinion, if I'm happier like this at night, should I still consider moving to a day schedule for health reasons alone?

Thank you for your time.