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Can Vitamin D Supplements Cause Insomnia

Can Vitamin D Supplements Cause Insomnia? (Sleep Naturally)

by Eric Sales De Andrade, March 25th 2021

Reading Time: 6 minutes

Are you tossing around in bed right now, wondering why you can’t get any sleep?

You’ve been taking Vitamin D supplements to stay on top of your levels and avoid deficiency but you’re wondering can Vitamin D supplements cause Insomnia?

There are several reasons for Insomnia. Some are obvious while some are more subtle and hard to pinpoint.

I’ve struggled with insomnia and it’s one of the most difficult things to endure for anyone.

I dived into the research, supplements, foods and lifestyle that could affect your ability to sleep.

I also share some best habits and proven practices on how to sleep better.

Can Vitamin D Supplements Cause Insomnia?

Researchers have studied and documented Vitamin D’s links to sleep quality.

Low Vitamin D causes problems like poor sleep quality, reduced sleep duration and sleep disturbances. More on this in the next point.

There were 2 studies done to understand the relationship between high Vitamin D and sleep.

One study was done in 2013 on women with multiple sclerosis to test the effect of high Vitamin D on melatonin (the hormone responsible for sleep).

They divided the group into two — women who took high Vitamin D (4,370 IU) and low Vitamin D (800 IU).

The group that took high Vitamin D had lower levels of melatonin in their blood and the other group didn’t.

The study didn’t take into account sleep quality so there was no conclusive evidence.

Another study done in 2016 on a group of post-menopausal patients trying to lose weight and taking 2,000 IU of Vitamin D a day (due to a deficiency) saw their sleep quality deteriorate.

They concluded that high vitamin D could result in poor sleep quality in people with post-menopausal symptoms who were already deficient in Vitamin D.

So if you’re wondering can Vitamin D supplements cause insomnia, due to research on a specific group of people under specific conditions, it’s hard to say whether high Vitamin D causes insomnia.

It’s recommended to take the correct dose of Vitamin D and during the day after a meal.

Can Vitamin D Supplements Cause Insomnia

Does Vitamin D Deficiency Cause Insomnia?

The quick answer is Yes.

To test this, 1,472 field workers from an electronics manufacturing plant in Changwon, South Korea underwent a special health exam.

Results showed a significant correlation between low Vitamin D levels and poor sleep quality in the workers.

As a result of this test, the company implemented a sleep disorder management program and free Vitamin D supplements.

There’s also a proven relation between Vitamin D and Chronic Fatigue so that’s another reason to check your levels more often.

Which Vitamins Keep You Awake At Night?

Now if you’re still awake and wondering, what else could be causing my insomnia?

There are supplements that may interfere with melatonin levels and sleep patterns. Let’s take a look.


The good old multivit. One tablet for everything. They often contain a very long list of ingredients you need to be aware of that could affect your ability to sleep.

Multivitamins may contain caffeine, green tea extract and CoQ10. These ingredients may interfere with sleep so it’s important to be aware.

Check the ingredients for caffeine or other stimuli and avoid taking more Vitamin D if your multivitamin already has Vitamin D.


Some of the B-Complex Vitamins may have a relationship with sleep patterns.

Vitamin B-6

Vitamin B-6 is also called Pyridoxine and in a small study done in 2002, few college students were given very large doses of B-6 and found to have vivid, colourful and memorable dreams.

This increased brain activity may affect your ability to sleep so it’s best to take B-6 during the day.

Vitamin B-12

Vitamin B-12 improves energy levels so if you take too much B-12 in the evenings it could leave you feeling energetic at night.

Jonathan Valdez, R.D.N and owner of Genki Nutrition says

For many reasons, B12 and the other B vitamins are popular supplements. However, since they get our metabolism moving and grooving, they can have a somewhat stimulating effect that messes with sleep when taken too late in the day


Calcium is an important mineral that strengthens bone density and promises good health.

Excess calcium may interfere with your body’s ability to absorb Magnesium.

Magnesium actually promotes relaxation and good sleep.

So you’re better off taking any calcium supplements during the day.

Herbal Supplements

Natural herbal supplements like Ashwagandha and Maca have a whole suite of awesome health benefits.

But they may contain tiny caffeine levels and interfere with your melatonin production and your ability to sleep.

Best Time Of Day To Take Vitamin D3?

Now that you know that being deficient or having high levels of Vitamin D may affect your ability to sleep, what’s is the best time of day to take Vitamin D?

Vitamin D is a fat-soluble vitamin, which means it needs to be taken with co-factors supplements and fat (or a meal) to maximise its absorption.

Take it during the day to avoid any interference with melatonin levels that may cause sleep problems.

Side Effects From Too Much Vitamin D

Fat-soluble vitamins (like Vitamin A, D, E, and K) have stronger effects on our body. This is because they get stored, unlike water-soluble ones (like Vitamin B, C) that get flushed out.

Being deficient or taking too much Vitamin D over a long period of time can have side effects like

  • High calcium levels (hypercalcemia) — May cause a deposit of calcium in the kidneys, liver and blood vessels.
  • Nausea and vomiting
  • Stomach pain and diarrhoea

Although rare, Vitamin D toxicity is possible so only take a high strength supplement if you’re deficient and stay on top of your levels.

Vitamin D Cofactors supplement like Vitamin K2, Magnesium, Boron, Omega 3 and Vitamin A also help reduce any calcium toxicity from strong Vitamin D supplements.

What Foods Can Cause Insomnia?

So we’ve discussed supplements and learnt about their impact on sleep.

But what about food, what foods can you avoid so your eyes shut the minute you hit that pillow?

Coffee and Caffeine

Not a lot of people know that besides coffee, green tea, dark chocolate and some sodas may contain caffeine.

Avoid coffee after 5 pm and next time you’re tucking into delicious late-night dark chocolate, check the label for caffeine.


Alcohol helps a lot of people fall asleep. But it affects your Rapid Eye Movement (REM) cycle which handles memory, concentration and feeling refreshed.

Deep sleep requires a good Rapid Eye Movement (REM) cycle.


Although nutritious, red meat like beef, chicken and lamb is hard to digest and your body needs to spend an incredible amount of energy.

Your digestive system generally slows down at night so eating meat means the body needs to work hard and this affects sleep.

Spicy Food

As much as you may love the occasional jalapeno and chilli sauce, spicy foods have the capacity to cause heartburn and acid reflux.

Lying down makes acid reflux worse and prevents you from getting a good night’s sleep.

Cup Of Black Coffee

Other Natural Ways to Improve Your Sleep

That said, what are some natural ways to improve sleep and reduce any possibility of insomnia.

1. Sleep At The Same Time

It’s very important you sleep at the same time every day.

Your Circadian rhythm (or body clock) handles biological and physiological functions in your body.

When you sleep at the same time every night your body gets used to it and develops a rhythm much like your dog knows when it’s time to eat or go for a walk.

2. Avoid Bluelight or use Bluelight Glasses

Blue light from your cell phone, laptop or television affects melatonin levels (the hormone responsible for sleep).

Avoid electronics at least 1 hour before bed or if you do feel the need, use blue light blocking glasses to protect your sleep hormones.

3. Create A Routine

A strong sleep routine will prepare you for sleep like no other.

Try reading fascinating stories or fiction, journaling, a warm bath and meditation.

These soothing practices heal and relax your mind and body in preparation for bedtime.

4. Environment

Ensure a comfortable temperature that doesn’t wake you up freezing or sweating at 3 am. Put the thermostat to something cool that feels comfy when you’re tucked into your duvet.

If you live in a warm country, sleep with minimal clothing that feels cool and comfortable.

Keep your room dark using shades or blinds so melatonin levels are not affected by that annoying street light outside your window.

5. Natural Supplements

While I’m a big fan of doing things the natural way, some people prefer to take natural supplements and adaptogens to ease stress and sleep better.

Some ingredients to help you sleep include Magnesium, L-Theanine, Chamomile, Lemon-Balm and 5-HTP.

Dark Room


So, in this article, we answered an important question – can Vitamin D supplements cause insomnia?

We also explored some natural ways to avoid insomnia and good sleeping habits and rituals.

Take your vitamins and supplements during the day, eat early and have a relaxing bedtime routine.

If you found this article helpful please share it.

Join our Vitamin D Fan Club — a private Facebook group.

Here you’ll connect with fellow health lovers and learn all things Vitamin D, all things natural supplements.


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