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Vitamin D and Sleep – What You Need to Know

Vitamin D: What it is and Why it Matters

Vitamin D plays an essential role in sleep quality and sleep regulation.

Your sleep quality is linked to your overall health. Low vitamin D levels or a vitamin D deficiency, can lead to poor sleep quality and a variety of sleep disorders and other significant health issues.

Before we go further, it would actually be more accurate to put the first word in our label Vitamin D in quotation marks (“Vitamin” D), since D is not actually a vitamin. It is a hormone.

Understanding that vitamin D is a hormone tells us that like thyroid, estrogen or testosterone, it affects multiple parts of the body and that it is not “extra”, it is essential.

Vitamin D Deficiency and Sleep Issues

Low vitamin D can turn healthy sleep into poor sleep. Maintaining a healthy D level is an important factor in reducing your chance of developing a sleep disturbance or sleep disorder.

The best way to have healthy levels of the hormone D is from the sun because we make the hormone naturally from sun exposure. That’s why vitamin D is sometimes called the ‘sunshine vitamin’.

Our ancestors spent lots of time outdoors in the sun and acquired D naturally. Therefore, they didn’t need to take vitamin D supplements in order to achieve normal sleep.


However, modern living has led many people to spend more time indoors, which results in us getting less vitamin D from sun exposure and low vitamin D levels. This could explain why sleep disorders and sleep-related health issues have been dramatically on the rise over the past forty years.

Sleep issues ranging from short sleep duration and excessive daytime sleepiness to sleep apnea, narcolepsy and insomnia can all be linked to low vitamin D levels.

The good news is that vitamin D supplementation can help you get your vitamin D level back on track if you are not able to get the consistent sun exposure required for a stable, healthy vitamin D level.

Is Vitamin D the Same as Vitamin D3?

It depends on what you mean by Vitamin D. If you mean, “Is Vitamin D2 the same as Vitamin D3?” the answer is no. D2 is an ancient chemical made only by fungus and none of the animals on this planet make it. Unfortunately, some doctors do not understand that D2 is not an appropriate substance to give to people.

Instead, you should be supplementing with D3, which is what the body naturally makes when exposed to the sun.

How Much Vitamin D Should You Take?

This is where things get a little more personal. Before starting a D supplementation regimen, you need to know your current vitamin D blood level.

Even though every vitamin D supplement bottle will have a “recommended” dose, it is impossible to know how much vitamin D you should be taking without seeing how your body responds to dosing, and how much D it takes to increase your vitamin D blood level.

An example from my neurology practice, where I first discovered how each of us responds uniquely to vitamin D dosing:

A mother is dosing three of her kids with 2,000 IU/day for one month in the winter, Nathan goes from 20 ng/ml to 50 ng/ml, Samantha goes from 18ng/ml to 25ng/ml and Alex goes from 25ng/ml to 95 ng/ml. Each was taking exactly the same dose for the same period of time!

The maximal amount of vitamin D made on the skin of a light skinned person, fully sun exposed, middle of the summer, is said to be 20,000 IU, so that is the largest dose that I will start even in someone whose level is very low (undetectable -10ng/ml).

There are some people that make and use much less.

About 1 in 50 people only need 2,000 IU/day. Every single person must have vitamin D blood levels done several times during the first year of supplementation to see what dose they need to maintain their vitamin D blood level at 60-80 ng/ml, (where best sleep occurs).

It is the D blood level, not the dose of the pill we take, that determines good health and optimal sleep.

Can You Overdose on Vitamin D?

Yes, you can overdose on vitamin D.

Since vitamin D is a hormone, it means that you can have serious consequences from taking too much. Unlike true vitamins like vitamin C, your body does not immediately eliminate excess vitamin D (because it is actually a hormone).

So, while vitamin D deficiency is linked to sleep (and health) issues; too high of a vitamin D level (through vitamin D supplementation) can also cause problems.

In other words, too much vitamin D is just as bad as too little.

What is the best time to take vitamin D?

Though some experts say you don’t have to supplement at an exact time, early to mid morning may be best, and is what I recommend to my clients, since that is when you would naturally be exposed to the most D through sun exposure.

Also, that’s often the easiest time to remember to take it so you don’t forget. That said, listen to your body. Everyone responds to supplementation differently. If taking D at night improves your sleep, then that is the right choice for you.

Most don’t realize that B vitamins also play a role in sleep…

Actually, Vitamin D is not the only thing that may be impacting your sleep, as it is only one of several important factors in your healing.

That’s why I recommend following the RIghtSleep Program using the RightSleep Workbook. The Workbook outlines best practices, the best test for an accurate vitamin D blood level, and related supplements which help repair related deficiencies and support the overall healing process.

The basic premise of RightSleep is that if you are not experiencing consistent, restorative sleep, your brain does not have the “raw materials” it needs to perform this function.

Vitamin D is one of those raw materials, but so are several B vitamins (such as vitamin B12, vitamin B5etc). The actual sleep control center in the brain uses a chemical that needs D plus certain B vitamins to help restore your sleep.

The RightSleep Program shares guidelines to direct your unique supplementation, including how and why B vitamins also play a role.

Get personal help with your sleep issues

The RightSleep® Program is AVAILABLE HERE!