A few weeks ago I got an email from a reader named Alexander Vinther:
I take Vitamin D3 (2000 units) in the morning (between 7 and 9 am) together with fish oil. My sleep is deeper and I don’t wake up at odd times during the night. I tried increasing my intake 3-fold [= to 6000 IU] but felt too energetic/restless when going to bed (regardless of the time). I stopped taking Vitamin D3 (the regular dose) for a while to check my results only to start waking up in the night (or waking up early). Before this, my intake of D3 and fish oil was usually in the evening (everybody seems to recommend taking vitamins in the evening). The change from evening to morning was with both fish oil and D3 (I have always been taking them simultaneously) with huge improvement in sleep.
This is especially interesting because he made the evening-to-morning change long before I blogged about it. I asked for details.
Tell me about yourself.
Male, 24 years old. I live in Denmark and study philosophy. I exercise a lot (6 times a week, crossfit).
What were your sleep and energy like before you started taking D3 and fish oil in the morning?
My energy levels during the day would change a lot, sometimes with a huge surge in energy in the evening making falling asleep difficult. This would lead to few hours of sleep or a general feeling of not having slept at all (this in comparison to what I feel now, the feeling of “deep” sleep). [This is what happened when he was taking D3 and fish oil in the evening. --Seth]
Have you tried other D3 dosages?
I started out with 1400 units of Vitamin D3. I now take a multivitamin which has a small amount of D3, hence the 2000 units. I didn’t notice a difference between 1400 and 2000 units, but 6000 made me giddy/restless for the first week, which is for as long as I tried that particular dosage. 4000 units seems to have the same effect as 2000 units, but it is a dosage I haven’t taken for more than a week.
How long have you been taking Vitamin D3 in the morning?
I switched the time (from evening to morning) of my D3 intake about a year ago. Stumbling upon your blog confirmed my belief in or underlined the evidence for a difference in morning/evening intake.
How soon after you started D3 and fish oil in the morning (instead of the evening) did you notice better sleep?
I would say I see improvements in my sleep 3-4 days after D3 intake
What brands of Vitamin D3 and fish oil do you use?
My D3 brand is Danish: Naturdrogeriet D Mega. My fish oil brand is Biosym EPA-GLA+. I take 2 capsules containing a total of 1200 mg fish oil (DHA, EPA, GLA), 600 mg Borago oil and 700 mg soyalecithin.