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Among these supplements, vitamin D seems the most likely cause. Multivitamins, fish oil, magnesium, calcium, vitamin K and protein supplements are not generally known to cause insomnia. High doses of vitamin D, as well as high blood levels of vitamin D have been associated a deterioration in sleep quality — and you seem to be supplementing with both vitamin D and a multivitamin that likely provides more vitamin D. High amounts of vitamin D may interfere with the body's production of melatonin. 

For more about this, see the Concerns and Cautions section of the Vitamin D Supplements Review. Also see the section How Much Is Too Much? regarding getting the right amount of vitamin D. 

Be aware that beta blocker medications, such as atenolol (Tenormin) and metoprolol (Lopressor, Toprol XL) that help lower blood pressure may also lower your body's nighttime production of melatonin and interfere with sleep. A small study suggests that melatonin supplementation may improve sleep in people taking these medications. However, be aware that melatonin may increase blood pressure in people taking another type of blood pressure lowering medication. See the Concerns and Cautions section of the Melatonin Supplements Review for more about this.

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June 14, 2020

Vitamin K can cause insomnia. Especially K2. I had to stop taking it as it really made me uptight and anxious.
June 15, 2020

Thank you for sharing this. As noted above, vitamin K is not generally known to cause insomnia and we are not aware of any published reports of this.

May 27, 2019

In the past I read that eating protein later in the day might contribute to sleeplessness, for what it's worth.

March 6, 2019

Hi, i’ve had terrible insomnia since taking berberine, but everywhere that I have researched it doesn’t say there is any link between insomnia and berberine, can you please let me know if you’ve heard of this before? Thanks
March 7, 2019

Hi Alexandra - There do not appear to be any reports of insomnia as a side effect of berberine supplementation. You can find more information about berberine side effects in the "Cautions and Concerns" section of the Berberine and Goldenseal Supplements Review:

February 27, 2019

Why is there never any information and warning about the high amounts of glutamate in protein powders and chelated supplements ? Our bodies are getting an overload of glutamate anyway, because it is hidden under so many different names in the food supply. I have ended up in the E.R. several times with severe side-effects like tachycardia, hyper-excitability, digestive problems and sensory changes in my arms and legs. I also can not fall asleep because I am so hyper. But when my diet is void of added sources of concentrated glutamate, I sleep like a baby.
See a listing of all the sources on a site like ' Hidden sources of MSG ,Truth in labeling campaign'. Reading it has changed my life and health for the better dramatically.
We all have a different threshold -I am extremely sensitive to it-, but at a certain level everybody will have a reaction .


June 20, 2018

What is considered to be a 'high amount''?
June 20, 2018

Hi Stephen - If you click on "Concerns and Cautions" link in the Answer it will take you to the section in the the Vitamin D Review that provides more detail (

February 22, 2018

For Tim & Joe-
What are the dosages for the 3 items you take and the timing? I too have interrupted sleep and wake at that "witching" hour of 3a. Thank you - Linda

Tim and Joe16487
February 21, 2018

I have had bad insomnia for several years (fall asleep no problem, but wake up at 3-3:30 am every morning). I too take vitamin D as I have an extreme deficiency. It will not hurt for you to try cutting out supplements to try and determine if one of them are affecting your sleep, but understand that our bodies change as we age, and there are side effects of these changes, and the answer may not be as simple as you hope. I have been on my quest for optimal sleep for five years now. I have learned a LOT about sleep, and more importantly all of the different bodily cycles responsible for sleep. It is odd that something so common - that we all MUST do - is so complicated and so heavily regulated by our bodies. Long story short, after trying EVERYTHING, it was determined that my Serotonin / Cortisol cycle was out of whack. For me, my deficiency in Vitamin D exacerbated the problem, and far from causing insomnia in me, I needed vitamin D for sleep. In the end, I take melatonin, tryptophan, and 5-HTP, and I now average 7 hours sleep per night. On those days where I wake at 3 am with the cortisol raging, I pop an additional 100mg 5-HTP and within a half hour I am back to sleep until 7-7:30
I guess what I am saying is that you are looking for a simple answer to a complex problem, and unfortunately, our bodies do not work that way. What works for one person, may not work for you, because the underlying problem may be very different, yet with the exact same result - lack of sleep.
February 22, 2018

Hi Tim and Joe - We are currently testing 5-HTP and tryptophan supplements and expect to publish a report this year. In the meantime, you may also find our review article on these supplements helpful:

February 20, 2018

I am unable to sleep when I take a multivitamin pill, even a childrens version, and over the years discovered I was extremely sensitive specifically to Vitamin E. Same for taking a vitamin D supplement. I can take a large dose (5 - 10,000 iu) of D once a week, but even a small dose (1000 iu) daily gives me insomnia. I learned that I am sensitive to all 4 oil soluble vitamins if taken in a dose even approaching 50% of the RDA. I think the problem could have to do with metabolism. Possibly a coincidence but I also have celiac sprue.

February 18, 2018

interested in comment about insomnia and vitamin d.

i have insomnia and take D3 (1000iu) plus my multi vitamin contains another 500iu.

interested in research on this subject.

can you refer to me this research as i could not locate anything about INSOMNIA / VIT. D

February 21, 2018

Hi Robert - Please use the link to the "Concerns and Cautions" section of the Vitamin D Supplements Review in the answer -- this section provides more details and the research on this.

January 3, 2019

I, too, suffered from insomnia when taking Vitamin D. I switched to AOR 'liquid' Vitamin D, taking it with my morning tea with a spot of cream. Within days, sleep improved.

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