Vitamin D and Sleep: The Sunshine Nutrient’s Role in Building Better Sleep

On June 29th, I started an experiment with Vitamin D and my sleep. As with most things these days for me, I found the information rather serendipitously through an inadvertent comment on one of Hypnagogia’s blog pages – a post made some months ago, but was commented on only recently. The comment led me to Seth Roberts, and a series of posts he had made about Vitamin D and sleep.


Vitamin D and Sleep

I was deeply interested in what Seth, and the comments on his blog, had said. Some examples:

A new study of a quarter million Copenhagen residents found that those with Vitamin D blood levels of 40-70 nmol/L [16-28 ng/ml] had the lowest death rate. People with lower and higher amounts had higher death rates, in other words. The death rate versus blood level function has a reverse-J shape, i.e., too little is worse than too much. About 1% of the sample had levels above 140 nmol/L [56 ng/ml], for practical purposes a “high” level.

Jim Breed has been taking large amounts of Vitamin D3 (5000-10000 IU/day) since 2008. Yet when he switched to taking it in the morning, his sleep quickly improved. Here’s what happened:

Via self-measurement I confirmed Tara Grant’s conclusion that taking Vitamin D3 in the morning (rather than later) improved her sleep. It improved my sleep, too. When I had taken it at other times of day I had noticed nothing. Apparently the timing of Vitamin D — the time of day that you take it — matters enormously. Take it at the right time in the morning: obvious good effect. Take it late in the evening: obvious bad effect. Vitamin D researchers haven’t realized this. They have neither controlled when Vitamin D is taken (in experiments) nor measured when it is taken (in surveys). Because timing matters so much it is as if they have done their research failing to control or measure dose. If you fail to control/measure dose, whatever conclusion you reach (good/no effect/bad) depends entirely on what dose your subjects happened to take. And you have no idea what dose that is.

Also read –

Other Vitamin D Follow-Up

I did some additional research and, as usual, found all kinds of conflicting information about Vitamin D and sleep. Almost all of it was anecdotal, with a couple of controlled experiments thrown in for good measure (population of one, so not very applicable). But there is a lot of anecdotal Vitamin D stuff out there, so I thought to give it a try. Interestingly, I found that timing of Vitamin D (take it in the morning, not the evening) was a thread that I kept reading. Seems that people have experienced taking it at night affects their sleep negatively, while if you take it in the morning it enhances it.

Vitamin D3 Dosage and Timing

On June 29th, I started to take 4000IU of Vitamin D3 in the morning. Do a search for Vitamin D in the search bar to see what I found…