Vitamin D3 and Sleep Update

A month ago I blogged about a “stunning discovery”: Primal Girl’s sleep got much better when she took Vitamin D3 in the early morning instead of much later (afternoon or evening). Others pointed out a similar observation: Taking Vitamin D3 in the evening caused insomnia. These observations suggest that Vitamin D3 resembles sunlight in its effect on sleep: morning exposure good, evening exposure bad. Sunlight, of course, is hard to control and sometimes hard to get (which is why Primal Girl tried Vitamin D3). Sunlight is also time-consuming: it takes an hour to get one hour of sunlight. The timing and dosage of Vitamin D3 is much easier to control.

Now I’ve tried it. This isn’t the first time. I’ve taken Vitamin D3 on and off several times through the years. Each time I didn’t notice any change so I stopped. But then I’d hear an interesting argument (never anything as clear as what Primal Girl found), and try again. And stop again. This time I took the Vitamin D3 around 8 am. (In previous attempts, I never controlled the timing and never took it early in the orning.) I started with 2000 IU/day. I did that for nine days. No clear effect. Then I increased the dose to 4000 IU/day. The change was unmistakeable: I started to wake up feeling somewhat more rested and, for the first time, with a pleasant warm feeling. So far it’s been eight days. Something is different and better.

I am writing about this now because the results are already interesting. My experience so far “proves” nothing, of course. Let me make clear the limitations: 1. You might consider the effect small. I was already sleeping well. I fell asleep quickly, did not wake up during the night, and woke up feeling rested. Now I wake up feeling more rested. 2. Eight days isn’t much. Maybe the effect will go away. 3. Maybe the effect doesn’t depend on time of day. I haven’t yet tried taking Vitamin D3 at other times of day.

Why do I think this is so important?

1. Sleep is central to health. You fight off infection while you are asleep. When I improved my sleep, I stopped getting noticeable colds. I’m sure if people slept better, they would get sick less often. Heart attacks are more common in the winter. People sleep worse in winter.

2. Sleep is a huge problem. As far as I can tell, most adult Americans complain about their sleep.

3. No one expected this. Nutrition researchers, dieticians, and so on obviously didn’t expect it. Nor did circadian rhythm researchers. They (or we) think that everyone, including plants, has one or more internal circadian clocks that is/are synchronized (= set) by the environment. The general public thinks that sunlight affects the clock. Lots of research supports this, but circadian-rhythm researchers know something the public does not: that those rhythms are also affected by the time of food and social contact. All three (sunlight, food, social contact) are part of the environment. Their power over our sleep makes sense (e.g., we should be awake when food is available.) Vitamin D3 is not part of the environment. Its power doesn’t make sense. No one in the paleo community expected this. Stone-Agers got a lot of sunshine, yes. They did not take Vitamin D3 pills. Sure, many in the paleo community praise Vitamin D3 but I have never heard anyone say you should take it in the morning.

4. Vitamin D3 is safe, cheap, and widely available. It probably has many benefits, not just better sleep.

5. Taking pills is easy. There presently are no safe sleeping pills. Nor are there any cheap sleeping pills. Nor will drug companies ever invent them, if the past is any guide.

28 thoughts on “Vitamin D3 and Sleep Update

  1. A note on your “safe, … widely available” comment. It seems some folks still doubt D3′s safety. When I order 2000 IU D3 online (from Swanson), I am warned it can’t be shipped to Canada. Turns out Canada limits vitamin D capsules to 1000 IU. That seems silly to me, you can always take more than one. But I live in the US, so it doesn’t matter.

    I only take D3 in the winter months, when Chicago’s climate keeps me indoors most days. Usually at my first meal. I can’t say I’ve ever noticed a difference on my sleep, but I’ve never tried more than 2000 IU/day.

  2. MikeW: yeah, it is pretty silly. In old people, they’ve done acute doses of hundreds of thousands of IUs, with reductions in mortality. So… Chronic is not acute, that is true, but still.

    > 5. Taking pills is easy. There presently are no safe sleeping pills. Nor are there any cheap sleeping pills. Nor will drug companies ever invent them, if the past is any guide.

    What’s wrong with melatonin?

  3. Glad to see some science and disclosures and boundaries behind this finding, Seth. A short search on Nexus and others did not yield any scientific literature about this. I think I just have a knee-jerk reaction when someone reports on something and it’s suddenly a “newthing.”

    Could it be that Primal Girlz really did make a deliberate discovery by blogging about her experience? Could be. But now let’s move on to other matters.

  4. I would also like to see more about D3 delivery methods and dosage. I currently take 10-15,000 IU/day and this seems perfect for me. Can you elaborate, perhaps in an eventual blog post so that the message is not buried in the comments, how do you take D3? Do you then have to eat something in the morning because it’s fat-soluble? I don’t like to eat in the morning, and I believe your personal findings also don’t justify breaking the fast first thing in the morning. How to get D3 then?

  5. I’ve been taking about 8,000 IU of it whenever I get up for several weeks now. I cannot separate out causes because I’ve also been losing about 2.5 pounds a week during this period, and have reduced my hemoglobin A1 C number (diabetes) substantially.

    But: I am amazed at the change in sleep, to wit, I need much less sleep and no longer need the roughly 1.5 hour nap in the afternoon. I do not have attacks of fatigue any more. I don’t know if this is solely the effect of losing weight, or if the Vitamin D is playing a role. In previous weight loss experiences nothing so dramatic has happened, so I’m inclined to think that the Vitamin D is having an effect.

    Does anyone know at what levels Vitamin D intake becomes “toxic” or unsafe?

  6. Tim, you wrote:

    But: I am amazed at the change in sleep, to wit, I need much less sleep and no longer need the roughly 1.5 hour nap in the afternoon. I do not have attacks of fatigue any more. I don’t know if this is solely the effect of losing weight, or if the Vitamin D is playing a role. In previous weight loss experiences nothing so dramatic has happened, so I’m inclined to think that the Vitamin D is having an effect.

    With 4000 IU/day I have noticed I am less tired in the afternoon. But I still take a nap. You have convinced me to try 6000 IU/day.

    How much less sleep do you need? In other words, how much were you sleeping before you started the Vitamin D3 and how much are you sleeping now? Weight loss certainly reduces sleep need but it would still be nice to know the details here.

  7. how do you take D3? Do you then have to eat something in the morning because it’s fat-soluble? I don’t like to eat in the morning, and I believe your personal findings also don’t justify breaking the fast first thing in the morning. How to get D3 then?

    I take my D3 in 1000 IU tablets. Tablets, not capsules. I suspect tablets are digested faster. I do not eat anything else, although I have a small amount of cream an hour or so later. Yeah, D3 is fat-soluble. I suppose I have enough fat already in my system. I do not eat for several hours after I take the D3, just as you say.

  8. “I suspect pills are digested faster.”

    Seth: Dr. William Davis of Heart Scan Blog, who monitors his patients’ blood levels of Vitamin D, claims that many pills don’t budge the serum D–they don’t get absorbed properly. He insists that Vitamin D should always be taken in oil (gelcaps or drops–I really like the Carlson drops, as I hate swallowing pills). He’s done this monitoring with thousands of patients, so I trust his observations.

  9. the centrality of vitamin D is clear in the literature.

    Shortage of vitamin D is related to most mortality causes, and the evidence sounds that the vitamin shortage is causing the health issues.

    Also, vitamin D shortage is unnatural. Ancestors wore not that much cloth. in Africa there is much sun. and no long winters.

    Also, evolution changes northerners to blonds with pale skin to get more vitamin D.

    Also, evolution made northerners having more health negative cholesterol in order to absorb more vitamin D.

    Enough?


  10. “I suspect pills are digested faster.”

    Seth: Dr. William Davis of Heart Scan Blog, who monitors his patients’ blood levels of Vitamin D, claims that many pills don’t budge the serum D–they don’t get absorbed properly. He insists that Vitamin D should always be taken in oil (gelcaps or drops–I really like the Carlson drops, as I hate swallowing pills). He’s done this monitoring with thousands of patients, so I trust his observations.

    I should have said “tablets” rather than “pills” but your comment still holds. Perhaps the fact that I eat a lot of butter explains why I am having good results with tablets — there is plenty of fat in my system already. Perhaps most of Dr. Davis’s patients are on low-fat diets. And that is why they have trouble with tablets.

  11. Hi Seth,
    You write:
    “How much less sleep do you need? In other words, how much were you sleeping before you started the Vitamin D3 and how much are you sleeping now? Weight loss certainly reduces sleep need but it would still be nice to know the details here.”

    My best estimate is that I went from needing about 9 hours to about 7.5 hours of sleep which is about where I am now. Upon reflection, what is most striking is that it happened very suddenly, shortly after I started the Vit D. There was no gradual period where I needed shorter naps, no transitional period. Suddenly I didn’t need the nap one day, and then didn’t the next, until I observed that I needed 2 naps over a 2 week period — both times for various reasons I had gone to bed late and gotten up early and the naps were a function of sleep deprivation. It is hard to believe that the weight loss could cause such a sudden dramatic change.

    Over this period I have not been as good about getting actual morning sunlight, probably because I see myself getting it in a pill…

  12. Tim, you write:

    My best estimate is that I went from needing about 9 hours to about 7.5 hours of sleep which is about where I am now. Upon reflection, what is most striking is that it happened very suddenly, shortly after I started the Vit D. There was no gradual period where I needed shorter naps, no transitional period. Suddenly I didn’t need the nap one day, and then didn’t the next, until I observed that I needed 2 naps over a 2 week period — both times for various reasons I had gone to bed late and gotten up early and the naps were a function of sleep deprivation. It is hard to believe that the weight loss could cause such a sudden dramatic change.

    I agree. That convinces me it was the Vitamin D, not the weight loss. I had a similar experience. One afternoon after I started taking it recently (at 8 am), I noticed I wasn’t tired in the afternoon. I was surprised. I have still been taking naps anyway, even though I need them less. As I said I am going to increase my dose of Vitamin D (from 4000 IU/day to 6000 IU/day) to see the larger dose has a bigger effect.

    What brand Vitamin D do you use? Is it Vitamin D3? Is it gelcaps or tablets? How many IU’s per pill? How much did it cost?

  13. Hi Seth,
    I’ve been taking Vitamin D3 by Nature Made, tablets, 2000 IU each. I usually have a little bit of food with it, the mush I make, which has a fair amount of almond meal and flax meal and other stuff so that I’m getting fat with it.

    I grab anywhere from 4 to 6 tablets as soon as I’m up. (Yes, I’m that sloppy about it.) I don’t recall the exact cost but I got this kind because the GNC health food store had a “buy 1 get 1 free” sale. I take the kind that is second from the left here:
    https://www.naturemade.com/Products/Segments/Vitamin-D

    It was not terribly expensive, maybe $15 for 440 tablets at 2000 IU each

    And FWIW: A group calling themselves “The Vitamin D Council” claims: “What exactly constitutes a toxic dose of vitamin D has yet to be determined, though it is possible this amount may vary with the individual.
    Published cases of toxicity, for which serum levels and dose are known, all involve intake of ? 40000 IU (1000 mcg) per day. 1 Two different cases involved intake of over 2,000,000 IU per day – both men survived.”

    https://www.vitamindcouncil.org/about-vitamin-d/what-is-vitamin-d/vitamin-d-toxicity/

    Sounds like little is known about Vitamin D toxicity.

  14. Seth,

    Is it possible you need MORE Vitamin D (4000 worked but 2000 didn’t) because you don’t take it with food? I also noticed persistent insomnia when I ate Vitamin D containing foods in the evening, such as salmon and yogurt. I stopped eating those foods, and had no insomnia but I never made the connection until Primal Girl’s experiences chronicled in your blog.

    I actually thought it was the flax seeds I added to the yogurt. Now I eat yogurt with flax seeds only in the morning, and my sleep is dramatically better. I swim several times a week at noon so my vitamin D levels are probably already high.


  15. Is it possible you need MORE Vitamin D (4000 worked but 2000 didn’t) because you don’t take it with food?

    It’s not only possible, it’s likely. But it’s easy and cheap to take one more pill, so it makes little difference.

  16. > No clear effect. Then I increased the dose to 4000 IU/day. The change was unmistakeable: I started to wake up feeling somewhat more rested and, for the first time, with a pleasant warm feeling. So far it’s been eight days. Something is different and better.

    Incidentally, have I mentioned yet that you really ought to get a Zeo or even just one of those little motion trackers? That would make your sleep observations a lot more interesting.

  17. Seth said: Perhaps most of Dr. Davis’s patients are on low-fat diets. And that is why they have trouble with tablets.

    Actually Dr. Davis advocates a low carb diet for his patients, with a particular focus on eliminating wheat.

    Since there is a lot of interest in and discussion of how much D3 should be taken, I thought I’d mention that Dr. Davis advocates checking the serum level of vitamin D in the body by use of the 25-hydroxy Vitamin D test from time to time. He suggests one should target a blood level of between 50-80 ng/mL year round for best results. Obviously, as Dr. Davis points out, it is the serum level that is important, not the dosage which will vary by individual and time of year.

    On the other hand, I will admit that I dose myself by how I feel, rather than going through the aggravation of obtaining and paying for the test. :-)


  18. Actually Dr. Davis advocates a low carb diet for his patients, with a particular focus on eliminating wheat.

    The problem is that Dr. Davis fails to advocate a high-saturated-fat diet. So his patients accept the conventional wisdom that saturated fat is very very bad.

  19. I’ve had some positive effects of an increased vitamin D-dosage (and/or fishoil) the last few days.

    brief history:

    Starting January I were at about 94 kg and 30% bodyfat. Started doing light if (first meal 13-14 last meal 22), light exercise and some bodyweight exercise. Lost some weight. Basically I’d start every morning with 1-2 cups of coffee with some milk and kept that up the whole time.

    By april i exchanged the light exercise for heavy weightlifting and also started eating much more protein.

    By August I were at 82 kg, lower bodyfat and much stronger.

    In early September I had a personal crisis and become somewhat depressed. Kept up the training and If, but started eating a lot of junk food and sugary drinks.

    Sometime in October I started taking fish oil caps, magnesium tablets and vitamin d3 gel caps. 4000 mg fish oil, 120 mg magnesium and 2400 iu D3, mostly taken in the morning or early part of the day. I didn’t really notice anything different.

    (I’ll note here that I live in Sweden and hence have very little sunlight exposure this time a year. I usually have very low energy during the winter.)

    By November I had gained about 12 kg, and while significantly stronger, clearly a big fat gain. Throughout October and November I’d become increasingly more listless, and in December it started becoming a big problem. At the level were I barely went outside and only did the dishes once a week and started missing the 2-3 times a week gym sessions completely.

    2 days ago I upped the dosage in D3 to 4000 iu and doubled the fishoil intake to 4000 mg (about half being omega3). The first night I become more energetic and today the difference in energy level is HUGE. I’ve cleaned the apartment, cooked a bunch of food and my level of anxiety has dropped by a lot. The only negative is that I do feel a small excess of slightly nervous energy and the need to move. It’s nowhere near a panic attack or manic state, but a little unpleasant (though far better than being lethargic).

    I haven’t thought much about the sleep aspect, as far as I can recall I’ve slept ok the last few months, with some early awakenings. Last day and today I’ve woken up 9 and 10:30, though I haven’t noticed anything different about the actual sleeping.

  20. My diet is very heavy on somewhat to very fatty cuts of meat, something like an average 4 eggs a day, fairly large amounts of dairy fat (whole milk, butter, cream and fermented cream), a little fruit, some vegetables, occasional potato or rice.

    Sugary drinks and junk food = coca cola (almost every day during the last few months), crisps (maybe 250-500 g a week), chocolate bars (4-5 a week). Mostly eaten to lessen anxiety, but occasionally due to intense cravings.

  21. i read/heard that high doses of Vitamin D3 can increase urination.
    Though i cannot find the source of this info. So i do not not know what the definition of a ‘high dose’ is in this case. just something to be aware of though as you increase your D3 intake. if you find yourself getting up in the night to go to the toilet this could be a factor.

  22. interesting post from Dr Kruse…including some info headed “How do you tell if you are taking too much Vitamin D to get to optimal?”. Here’s some of the text:
    “….Vitamin A deficiency affects vision by inhibiting the production of rhodopsin, the eye pigment responsible for sensing low light situations. Rhodopsin is found in the retina and is composed of retinal, which is an active form of vitamin A, and opsin a protein made by the retina. Basically, if you “over do” the use of Vitamin D3, you will not make enough rhodopsin (from a relative Vitamin A deficiency) and you will suffer from night blindness. I pick this up in patients who notice night time visual driving issues…..” https://jackkruse.com/what-can-you-find-about-your-own-health/

    Paul Jaminet has also mention the A/D3/K2 balance in his posts & book.

  23. Late to the party here, but wanted to report my experience. I was feeling really down and depressed without knowing why when this post came out. Then I realized that I just don’t get enough sunlight at this time of year, so I started on 5000iu of D3 in the morning (Nature’s Bounty Brand, gel caps, with breakfast) and the difference in my mood is amazing. I have much more energy and depressive thoughts are gone since I started on the D3. The difference was noticeable in 2 days. No apparent difference in sleep or weight for me, however. Thanks for the reminder of the importance of vitamin D.

  24. Hi Seth,

    MOOD:
    I’ve been taking vitamin D for about a month now. When I first started taking it (1000-2000 IU), I noticed that my mood improved. I was getting depressed I think… there was a very heavy feeling, but I couldn’t explain why that was the case or what I should do about. However, it was a very similar feeling to what I had years before when I had a very long depression, so I was quite sure I was walking down the path again.

    After regularly taking vitamin D as soon as I woke up, my mood improved considerably. It is like the heaviness just disappeared. I did not yet notice improvements in my sleep however, until I upped the dosage to 4000 IU.

    SLEEP:
    Since being on 4000 IU (taken as soon as I woke up on an empty stomach with a glass of water or green tea), I have noticed remarkable changes in my sleep.

    The first is that, as you and Primal Girl have put it, I started feeling sleepy by 9-10PM. As a night owl who sleeps at different hours (although always sleeping for 8 hours no matter), it was an interesting feeling to receive these indicators from my body that I should sleep at 9-10PM. However, I do not always comply with these indicators (see 3rd point).

    Secondly, like Guv mentioned above, I started waking frequently to urinate at night. This somehow always occur around 5-6AM.

    Thirdly, I have been measuring my sleep-wake interval for about 2 months now. In the period that I took 4000 IU, I noticed that my sleep quality improved drastically! Despite waking at night to urinate AND despite nights where I only managed a total of 6 hours sleep instead of 8, I would wake up with lots of energy! It was the kind of waking up from a sleep then feeling, “Oh, I cannot go back to sleep anymore now, let’s get out of bed”, whereas before, any time I slept less than 8 hours, I just could not get out of bed, was not alert, wanted to continue to sleep….
    For me this effect is quite remarkable.

    I’m going to continue measuring this effect. I am also considering lowering the dosage to see what will happen.

  25. Hmm I was debating whether I should mention this because it is only a hypothesis on my part at the moment.

    On the days when i slept less than 8 hours but still woke up feeling very awake, I felt like my body WANTED to wake up despite whatever amount of sleep I got.

    It seems as if my body has shifted from a sleep-quantity state to a state where it needs to be awake no matter what at a certain time. I’m not sure if I am explaining this well. It is like the reverse of the sleep-indicators that my body was telling me around 9-10PM that I should sleep. Instead of telling me to sleep, it is now telling me to wake…

    For me this is quite a marked change. I have tried, unsuccessfully, for many years, to regularize my wake hour. My body used to refuse to be awake unless I had 8 hours of sleep. That 8 hours was so constant, it seemed as if ingrained in my body that I need 8 hours of sleep otherwise I would wake up in a “fog”. Also, when I used to sleep without the alarm clock, I would wake up after 8 hours of sleep, no matter whatever the time I slept was.

    Now however… I think there is a subtle change.
    Instead of 8-hours quantity, my body seems to go by a different signal. I am not quite sure what it is. I have only noticed this recently and am still investigating it, however, I decided to type it up as well in case anyone else has had the same effect or any theories as to why this is occuring.

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