Greg Harrington left a comment on an earlier post:

I have had very similar results [fall asleep more easily] from first-thing in morning D3.(NOTE: I have great flexibility in my schedule — I can sleep/awake whenever I want — so I have been most focused on “restful” sleeping.) Differences: (a) My pre-D3 issue was restless sleep (waking up frequently), not failure to fall asleep. (b) The effect of sleeping all the way through the night was definitely immediate–very first night. (c) Also, most days I also wake up feeling more “rejuvenated”. This is not 100% though.

I asked him for details.

Tell me about yourself.

I’ve lived Austin,TX since 07/2011. Kansas City, MO before that. I’m a software programmer. 6′ 3″. 210 lbs. (White male, mostly German, but completely European descent.)

How did you want to improve your sleep?

I want to sleep through the night without waking up 3-6 times in a 6-9 hour sleep. This problem has lasted for 2-3 years. It sort of crept up on me. I go to sleep between midnight and 2 am.

How much D3 do you take? At what time?

I take 50,000 IU between 8 and 9 am. If I forget or wake up later, I don’t take it. This is the product I take: Bio-Tech D3 in 50,000 IU capsules.

Why 50k? It was available on Amazon, and I calculated that to be what you’d get from 75-90 minutes of full-body sunlight. Thinking about Paleo lifestyle…that seemed reasonable. This is a LOT more than most SE people are taking but I wanted to maximize the effect!

Any effects of D3 on something other than sleep?

I often waking up feeling more rested/rejuvenated. But not every day. I tend to feel tired between 11 pm and midnight.

What happened when you started taking D3 in the morning?

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).

A reader named Tim G commented:

Blood tests last year [2011] showed I had low Vitamin D levels so I was put on a 50,000 IU once/week regimen for 3 months using a prescription D2 (ergocalciferol). A recheck after 3 months showed my level had hardly changed. A search of PubMed showed conflicting views on using the D2 form. So for the next 3 months I used ProHealth D3 Extreme 50,000 IU (via Amazon.com) instead of another D2 scrip my doc had given me. I always took the D2 or D3 in the morning (just lucky happenstance.)

The second recheck, after the second 3 mo., showed my Vitamin D level was normal. I hadn’t put it all together until seeing this post, but when using the D3 I had the same effect [as what is described in this post] — when I got tired, I got *really* tired right at bedtime, and slept like a rock.

Even though it has been less than a month since stopping the weekly dose, I have noticed my sleep degrading somewhat, and lately not even being tired when I should.

I asked for details:

Tell me about yourself.

I’m a 50 year old reasonably healthy guy who is a lifetime Massachusetts resident. I’m in the IT profession (managing computer systems, programming and such). So I am someone who 1) lives at a higher latitude, 2) during the day garners minimal Vitamin D from the glow of LCD displays and fluorescent lights, and also 3) generally dislikes the heat of summer and burns easily.

Why did you take D3 once/week rather than once/day?

My intent was to mimic the original doctor’s prescription of a single 50K/wk dose, while substituting D3 for the prescribed D2. At the time, I had no good reason to change to a daily schedule, although it intuitively struck me as odd to take a single large dose rather than smaller, more evenly distributed doses.

What time in the morning did you take it? What time do you get up in the morning?

I get up around 6-6:30 am. I would take the D3 around 6:15-6:45 am.

Why did your doctor prescribe D2 rather than D3?

I think it was simply rote procedure and cost. When I asked him after my first 3 months on D2, he said that the prescription D2 was cheaper than the prescription D3, and that he had seen the D2 usually work quite well to bring up Vitamin D levels, although it did sometimes take multiple 3-month courses to achieve normal levels. He seemed unaware of the literature criticizing the use of D2 as a supplement.

You write: “When using the D3 I had the same effect of when I got tired, I got *really* tired right at bedtime, and slept like a rock” What was it like when you were taking the D2? What was your sleep like before you started the D2?

To the best of my recollection I did not have a similar response when taking D2. However, since this was not something I intentionally tracked, I may be mistaken.

Before taking D2 or D3 I thought I slept reasonably well. However, in retrospect, I would awake a few times during the night, take longer to fall asleep, and awaken less refreshed than with my “Vitamin D sleep”.

You write: “not being tired when I should” — when is that?

What I meant is that when I’d get into bed at night, rather than feel tired (in the sense of “an onset to sleep”, not “worn out”) I would feel either wide awake or worn out, or both. By contrast, when taking the D3, almost as soon as I would lie down in bed I would feel an onset to sleep. Yesterday morning, I took one of my leftover 50K D3 pills and last night’s sleep did seem to confirm the efficacy of the D3.

When you took the D3 once per week, you slept better every night? Or just the night after you took the D3?

To the best of my recollection, I slept well every night. I don’t recall there being any noticeable variance relative to the day I took it.

Addendum by Seth. It is impressive that two things appear true: (a) the time of day D3 is taken mattered (other stories) and (b) a dose once/week at the right time improved sleep for seven nights (this story). The combination of the two supports the idea that our sleep is controlled by an oscillator and D3 at the right time gives that oscillator a push, increasing its amplitude.

Jenny West, the Englishwoman who discovered independently the value of taking Vitamin D3 in the morning, wrote again:

Since reading some of the other D3 stories, I increased my D3 [morning] dosage to 5000 IU/day [from 3000 IU/day] two days ago.

1. I immediately slept even better – no longer being aware of mid-sleep turning-over.

2. I’ve had a large boost of energy and the clarity of thought that both Robin Barooah and Alexandra Carmichael mentioned.

3. A year-long injury – specifically a dislocated coccyx – has suddenly taken a step forward, and I found myself running for the Tube last night – something I can’t remember when I last did it. Is this a direct effect of the D3, or an indirect one resulting from much better sleep?

This agrees with what both Alexandra and I experienced: a dose of 4000 IU worked much better than a dose of 2000 IU.

I have heard many stories about Vitamin D3 and sleep, often in the comments section of this blog. From now on I am going to number them. (I retitled earlier posts.)

Elizabeth Funderburk emailed me:

I’ve always suffered, rather lightly I guess, from SAD in the winter. In 2010 I started eating primal, which I thought would help – it helped in many ways but I still got gloomier all winter and didn’t even realize it til that first warm sunny spring day when I “woke up.” Your November post about D3 reminded me that I wanted to try it this winter, so I got a bottle and started taking it in the morning. I forgot a few times and took it in the midday or afternoon, and yes, I felt noticeably more spazzy and awake those evenings. Now, if I forget, I just skip it if I remember later than 10 am. I do think I sleep better. I take 4000-6000 IU daily.

I asked her for details.

Tell me about yourself.

I live in Reno, NV, USA, and I’m 34. I do home renovations.

What brand?

Kirkland D3 2000 IU gelcaps. The first bottle I got was from Walgreen’s, so I guess it was Nature’s Bounty gelcaps. Both seem to work equally well. I have not tried capsules. I take the D3 while I’m waiting for my coffee, usually 6 or 7 am.

How has your sleep improved?

With D3, I would guess I fall asleep in 10-30 minutes most of the time (trouble falling asleep once every 7-10 days). The wave noise thing by my bed is on a 45 minute timer. If the wave sounds stop and I’m still laying there conscious, I categorize that as a “trouble falling asleep” night and I will usually get back up and read for an hour.
In the fall before I started the D3, I’d take more than 45 minutes to fall asleep more often than after starting D3.

But I think more importantly, the quality of my sleep was not restful more often before D3 – I slept well (lightly, vivid dreams, woke up briefly, woke up feeling rested) maybe twice a week. I slept poorly (heavy, dark pit of sleep, no remembered dreams, unwilling to wake up and get up) 5 nights a week. It’s pretty binary; I usually sleep well or poorly, not “so-so.” Now, taking D3, I sleep well 6 nights a week, and poorly once a week.

What do you mean by “spazzy” (“more spazzy in the evening”)?

When I did take it in the afternoon, I noticed that I felt energetic when I’d prefer to feel sleepy – really raring to go at 7 or 8 instead of starting to wind down. I think it would be a fabulous tool for people working swing or graveyard shifts!

“thanks for the reminder” — you mean you had read elsewhere that Vitamin D3 first thing in the morning is a good idea?

You gave me the idea to take it IN THE MORNING. You “reminded” me about it in the sense that it’s one of the few supplements Mark Sisson (mark’s daily apple) suggests everybody could benefit from – I noted that when I gave up grain and started eating primal in early 2010, but it wasn’t something I’d bothered to take at that point, because I spend a lot of time outside in the spring/summer/fall. (Winter, too, but because I’m all covered up in clothes and the sun is so weak, I don’t seem to get the natural level of D3 I need.)

A woman named Jenny West, who lives in Chiltern Hills (west of London), commented that she “discovered independently that D3 first thing in the morning works.” I asked her for details:

I (and my family) started to take Vitamin D3 because we are all dyslexic/dyspraxic and had Seasonal Affective Disorder (SAD, a type of depression). Previously we had tried using light boxes (minimal effect), getting out every lunchtime (more useful) and finally 5HTp — which works but is expensive and if you start it once you are in SAD you can end up ‘wired’. Our SAD symptoms were mainly sleepiness and lack of energy (= hibernation), and brain fog (= difficulty concentrating).

We started taking D3 (2000 IU, Solgar) in gelcaps. That first winter, for the first time ever, no one had any seasonal affective disorder. I had had it since the age of 21, my youngest child when only 4 yrs old, and my other two children by the time they were 18 yrs old. At this point, we were taking the D3 at random times, commonly lunchtime or later, often when everyone was together and the vitamin pot was handed around!

This autumn, all the youngsters had moved out. I found I was forgetting the D3, so I moved it to the bathroom and started taking it first thing in the morning (8-9 am). Then in September, I started taking 3000 IU (instead of 2000 IU). We’d been in Greece and had come back to a gloomy autumn and I wanted to make sure SAD didn’t kick in. In a month I started sleeping through the night most nights.

Before I started taking D3 first thing in the morning, I only slept through 10% of my nights, and had been doing so for at least 15 years. I would wake at 3-4 am, but didn’t get up unless I had been awake for more than 3/4 hr. Then I would be awake until 6 am. Now I sleep without a break (other than turning over) from midnight to 8 am. I sleep like this 95% of my nights, and that includes the odd night when I took the D3 much later in the morning because I had slept in – and consequently woke the following night.

As a coeliac, I take the supplements many coeliacs take – probiotics, minerals, vitamins – but none of these affected my sleep either way. So it really looks as if it is the timing plus the correct dose of D3.

BTW the extra daytime energy is fantastic.

She is 5 feet 4 inches, 64 kg. Notice that 2000 IU first thing in the morning did not improve her sleep but 3000 IU first thing in the morning did. I had a similar experience: 2000 IU had no clear effect but 4000 IU did.

On a status update, Alexandra Carmichael (of CureTogether) noted she was taking 4000 IU of Vitamin D3. I asked her for details:

I’ve been taking 2000 IU of D3 every morning for many months, but after hearing about your Meetup talk topic from Gary/Ernesto [“Vitamin D3 and Sleep”] and talking to [redacted] about his experience with it, I decided to switch to 4000 IU, starting yesterday. I take it between 6 and 7 am, with my other morning supplements/meds.

Yesterday I noticed an unusual sense of “clear and smooth” mood for much of the day, which is very odd for me. The day after a meetup, I usually experience intensely fluctuating moods (I’ve been tracking hourly moods, and on my worst days, it’s a 3-hour cycle between peaks, like a super rapid cycling, ultradian bipolar – my therapist suggested this term when I showed him my mood tracking data.)

I also slept unusually well – I’ve been having a good deal of trouble sleeping lately, both falling asleep and night waking. Last night I slept a solid 8 hours!!!

That’s a very small sample (one day) of what happens with 4000 IU. However, Alexandra’s experience is similar to mine. I found that 2000 IU of D3 had no clear effect compared to nothing. However, the very first night after I upped the dose to 4000 IU (from 2000 IU) my sleep was noticeably better.

Alex is using Nature’s Bounty 2000 IU Vitamin D3 gelcaps.