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.