Vitamin D3 in Morning Has Ambiguous Effects on Sleep and Energy (Story 15)

A reader named Murray Love made a comment about Vitamin D3 and sleep that at least sounds negative:

As a counterpoint [to this post], I’ve been taking 4-5,000 IU of D3 for a couple of months now, and while it might be making me feel better in other ways (more vital, upbeat, and energetic), it has coincided with a stretch of poor sleep. I have what they (hilariously) call “terminal insomnia” — that is, I usually have no trouble at all falling asleep, but I wake regularly at night and am permanently awake very early, often from 4:30am onwards. This has been a periodic problem for a few years now, though this stretch is notably tolerable, for some reason.

I asked for details:

Tell me about yourself.

I’m an engineer, Victoria, BC, age 44. A big confounding factor with me is that I started a new job in November, for which I get up at 6 am and (on most days) ride my bicycle about 12 km (7.5 mi) to work, instead of walking a few blocks as I did with my previous job. I started taking the D3 and having this round of sleep problems all within a few weeks of starting the new job, so it’s difficult to disentangle all the correlations.

What time of day do you take the D3? What brand?

I take it around 6:30 am with my coffee. London Drugs (generic Canadian drugstore brand) 1000 IU tablets, though I’d prefer higher-IU gelcaps for ease of swallowing. I usually don’t eat anything for breakfast unless I’m cooking for my sons, in which case it’s meat and eggs with some fruit. Other times, when I’m not cooking but feeling hungrier than the norm at that time of day, I’ll have a handful of almonds or mixed nuts around the same time as the D3.

You started taking D3 because of my posts about it?

That sparked my interest, since I thought it might help with early-morning insomnia. But I’ve also been reading about the benefits of D3 for a while, such as at Dennis Mangan’s blog here and here.

You write: “This has been a periodic problem for a few years now,” What do you mean by “periodic”? For the last few years — before the D3 — on what fraction of nights did you have this problem?

“Periodic” means that I experience it almost every day (weekends included) for several weeks or a few months at a time, then it goes away for some reason and I sleep more normally for several months. The usual pattern for my insomnia is: I go to bed at 10:30, give or take 90 minutes, fall asleep almost immediately, wake up 1-2 times during the night (usually briefly), then around 4:30 am wake up and either a) doze lightly and intermittently until my 6 am get-up time, or b) stay awake.

Since you started the D3, on what fraction of nights do you have this problem?

I’d guess 85%. Once in a while, I manage to get some catch-up sleep and surprise myself by sleeping in.

You write: “this stretch is notably tolerable, for some reason.” Could you say more about this? What do you mean by “notably tolerable”?

It means I am surprised that my typical 4.5- to 7-hour sleeps do not seem to be affecting my energy level, mood, or ability to concentrate, even over several days. Since I went low-carb mixed with intermittent fasting back in 2008, I don’t tend to get mid-morning or early-afternoon energy dips, but since I started taking D3 (NB. plus new job, plus riding my bike again) I seem to be much more alert and cheerful, almost regardless of sleep. My experience seems remarkably similar to the other reader’s comment you posted this morning (27-Jan).

9 Replies to “Vitamin D3 in Morning Has Ambiguous Effects on Sleep and Energy (Story 15)”

  1. My own experience.

    I have irregularly taken 1000 UI in the morning for years with no noticeable effect.

    For about two years, I have had poor sleeping patterns characterized mostly by the fact that I tend to go to bed at 1am or later (and then I get up around 7h15 am). Whenever I would try to go to bed earlier, I would simply fail to fall asleep.

    After reading this blog, I increased my intake of D3 to 4-5,000 IU. I’m now falling asleep about an hour earlier. This could be a placebo effect, of course, but I consider it a very significant improvement.

    It is unclear whether I have more energy. I don’t know how to measure such an effect. I expect that I’m less irritable, but that’s a side-effect of getting more sleep.

    I plan to continue to see whether the effect is sustained over months.

  2. “…for which I get up at 6 am and (on most days) ride my bicycle about 12 km (7.5 mi) to work,…”

    High-intensity early morning exercise can cause people to wake up earlier than expected. I used to do heavy cardio first thing when I woke up but noticed I would wake up 1-2 hours earlier with my heart beating fast and I would not be able to fall back asleep. The problem went away when I stopped exercising early in the AM.

  3. I have WEAK evidence that taking 4000 IU Vit D at 8am will cause me to wake spontaneously at 6am. I have no trouble going back to sleep.

    The sample size is small and I conjecture that the dosage is insufficient because the Vit D is not making me tired.

  4. I also have terminal insomnia and also have found no effect on sleep from taking Vit D3 early in the morning. In fact, I also feel my sleep might be a bit worse from it.

    I do wonder though if there is perhaps some genetic variability at work here. My ancestors are from Northern Europe/Scandanavia. If they lived in that part of the world for many thousands of years wouldn’t it be possible that they evolved a different way of handling Vit D, (perhaps a need for less, a super efficient way of handling small amounts, a preference for D from a different source (fish liver) for example) from those ancestors who lived in warmer, sunnier climates over the same period, and who consequently didn’t have a need to modify the way they handled Vitamin D.

  5. Hey Murray,

    I started taking Vitamin D with gelcaps (on sale), and had good results. (I always slept well, but seemed more alert during the day.) But then my frugality kicked in, and I bought the tablets from Walmart, probably similar to the London Drugs. They don’t seem to have the same effect, so I wonder if active ingredient works as well. I will have to bite the bullet and try the gelcaps again.

    Regarding why “this stretch is notably more tolerant”, it could be that this new job situation is making the difference. I know I slept much better… 🙂

  6. 5,000 IU of D3 wakes me up for a few hours and then I am very tired, needing a nap. 50,000 IU kept me up all day. I think my body needs a constant dose of it every few hours and “withdrawal” induces sleep.

  7. My immediate reaction to this was: “He’s drinking too much coffee.” Not that I could actually know that, but when I drink more than 2 cups a day this “terminal insomnia” thing happens to me until I cut back. Just a thought.

  8. I do drink a lot of coffee, yes. Two or three cups of strong coffee between 6:15-7:15am, and then another two or three (of far inferior quality) at work between 8-11am. I don’t usually drink coffee in the afternoon. What’s the half-life of caffeine in the bloodstream? Around 5-6 hours, apparently, so maybe there’s enough remaining to interrupt sleep.

    Maybe I’ll give up coffee for Lent one of these years and see what happens, but the fact remains that the insomnia comes and goes while my coffee consumption remains more or less constant. And if I had to choose between coffee and getting a bit more sleep … I might well choose the coffee, especially since the insomnia doesn’t seem to be affecting my functioning this time.

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