When is the best time to take your vitamin D supplement?
Posted on 16 March 2010
While walking the dog today, my mind wandered and I found myself thinking about nutrient absorption. I’d just had lunch (leftover roast pork from yesterday) and some veggies and salad including rocket (a type of lettuce). My girlfriend dished it up and all I had to do was add a drizzle of olive oil to the rocket before serving. I like the taste and texture of olive oil on salad leaves. However, there is another reason for adding oil to salad – it enhances the absorption of so-called carotenoid nutrients. See here for more on this.
Thinking about this as I walked the dog got me thinking about other nutrients. If someone supplements with nutrients, say, what factors might affect absorption? I generally advise individuals who take vitamin and mineral supplements to take them with food. My rationale is that supplements are more likely to be ‘digested’ and nutrients absorbed when the digestive tract is in the throes of digesting and absorbing food. It suddenly occurred to me to look to see if there was any research on this.
A cursory search of the literature did not immediately reveal anything noteworthy regarding the absorption of nutrients generally, but I did find one interesting study that caught my eye. It concerned the absorption of one particular nutrient – vitamin D [1]. It piqued my interest partly because vitamin D appears to be such an important nutrient. But also, I’m taking it myself, in an effort to optimise my vitamin D levels.
This study focused on a group of individuals who were taking 1000 – 50,000 IUs of vitamin D (that’s not a typo, this upper dose is indeed fifty thousand IUs) each day as part of the medical management advised at a bone clinic in the US. Mean levels of vitamin D at the start of the study were 30.5 ng/ml (76 nmol/l). This level of vitamin D would generally be considered ‘sub-optimal’.
In an effort to boost absorption of vitamin D, individuals were asked to take their vitamin D supplements with the largest meal of the day. After 2-3 months, vitamin D levels were checked again.
At the end of the study period, vitamin D levels had risen to an average of 47.2 ng/ml (118 nmol/l) – an average increase in vitamin D levels of about 57 per cent.
This study is somewhat hampered by the fact that it lacked a control group – in this case a group of individuals who continued to take their vitamin D ‘normally’ (not, explicitly, at the biggest meal of the day). It’s possible, for instance, that the individuals in this study got, say, more sun exposure during the study and it is this that accounted for the rise in vitamin D levels.
Nevertheless, it seems sensible, I think, for individuals who are currently supplementing with vitamin D to take this with their largest evening meal. It doesn’t cost anything, and may provide supplementers with more bang for their buck.
References:
1. Mulligan GB, et al. Taking vitamin D with the largest meal improves absorption and results in higher serum levels of 25-hydroxyvitamin D. J Bone Miner Res. 8th February 2010 [epud ahead of print publication]
Published March 16, 2010 . Filed under: Healthy Eating, Nutrients and Supplements, Sunlight
Just a thought here. I have read and experienced Vitamin D3 disturbing sleep when taken in the evening say with the evening meal which for most people I know is the largest meal of the day. I take mine in the morning and my D3 level has come up to 72 ng/ml from 23 ng/ml, taking 5000 IU per day for the year.
March 16, 2010 @ 6:47 pm
Yes, I have also heard (I forgot where, I should say “read” as it was online) that D can keep some people awake if taken in the evening. Up to the individual – as long as breakfast contains an appropriate amount of fat (I’m talking butter, cream, coconut oil) then I imagine taking it in the morning is fine. It’s sunnier in the morning after all!
March 16, 2010 @ 11:55 pm
Dr. Briffa,
It is good to read another great, and accurate article about vitamin D. I just wanted to call your attention to a great organization that is trying to get the word out about vitamin D deficiency. They concentrate on the science behind vitamin D and educating the world.
Check out http://www.grassrootshealth.net/events for their upcoming seminar. It will have amazing new research about vitamin D.
Thanks!
March 17, 2010 @ 1:57 am
There has been some discussion that, due to the fact that we make vitamin D during the day, that vitamin D may be involved in some sort of circadian rhythm regulation (which wouldn’t be surprising given how much it is involved in everything else!). Therefore, taking vitamin D too close to bed time may lead to disturbed sleep.
I have taken vitamin D at both ends of the day and can’t say I noticed too much of a disruption. However, I now take vitamin D in the morning with sources of fat (coconut or coconut oil usually) as I figure I may as well give it to my body when it would normally expect to get it anyway.
March 17, 2010 @ 9:41 am
Jamie
By coincidence, I was talking to a journalist yesterday who told me she had recently spoken to a sleep specialist in Scotland who has found, clinically, the correcting vit D deficiency generally helps sleep. No info on timing, but I thought this was interesting as I’d never heard/read about any link between vit D and sleep before.
March 17, 2010 @ 9:53 am
I, too, have heard (albeit anecdotally) that large amounts of D3 later in the day/evening can disrupt sleep. I would assume through some type of circadian rhythm disruption secondary to hormonal secretion, like Jamie stated. Personally, I’ve always taken my D3 either post-breakfast (high fat), or split it between morning and post-workout
It would be interesting to hear more about this, Dr. Briffa
March 17, 2010 @ 8:32 pm
Perhaps, as is the case with many compounds in the body, the signs and symptoms of deficiency & excess manifest exactly the same. This holds true to some extent for the likes of iron deficiency & iron overload. Vitamin D could well be the same.
In a vitamin D deficient state, the benefits of vitamin D supplementation improve sleep & the magnitude of this is sufficient to negate any issues with the timing of doses. As vitamin D levels normalise however, or approach upper physiological ranges, a response to dose timing may become more apparent, with doses taken later at night causing sleep disruption?
No data – just throwing some thoughts out there.
March 17, 2010 @ 9:22 pm
Timing is interesting. In natural circumstances the “dose” of D depends on the duration and intensity of sun exposure (UVB) and also on recent history of such exposure (ie due to destruction of excess vitamin D when a lot of recent sun exposure ie in preceding hours has occurred). My interest is in achieving the optimum effect for health and on that basis I think that split oral dosages may be more beneficial (when sensible sun exposure is not possible) ie the argument being that you are trying to simulate variation in sun exposure over the day. However, there may also be differences in effect based on the route of exposure (whether there is or not is not really known at this point, however, Prof Holick has speculated about this and I think he may have a good point)
Using the same mind set taking a lot of D just before bed time may not be the way to go, split between breakfast and evening meal may be better- make sure to eat some fat too as vitamin D is a fat soluble vitamin and this will assist with its absorption.
OB
March 18, 2010 @ 11:26 am
I’ve heard that since Vitamin D is fat soluble, you should try and take it with some oil or other fat. Not sure about this, but I always take the vitamin D capsules together with my Omega-3 oil for that reason.
March 18, 2010 @ 7:11 pm
It’s a little freaky to see 30.5 ng/ml referred to as sub-optimal levels of Vitamin D. Mine was at 13 a few month ago. I wonder what terminology relates to that. I did the 50000 units once a week for 2 months. The retest showed I was up to 24. Yea! Now another course and maybe I will surpass sub-optimal.
March 19, 2010 @ 3:09 am
Interesting to read Karen’s post. Most people thing 50,000 IU per day is ‘extreme’. Given how long it takes people like Karen to get to 24 ng/ml on 50,000 IU a day (still sub-optimal), I think it’s about time we all got away from being frightened of 50,000 IU a day.
‘ve been taking 50,000 IU a day for several years. I decided to go back to taking 10,000 IU a day about five months ago. Guess what? I’ve had all sorts of viral infections in the past three months, ones I’ve not ever had on the highest dose and ones which are still ongoing!
I’m back on 50,000 IU a day. I’m feeling better after one or two days on this highest dose, after weeks and weeks of a viral infection. It’s the only dosage that works for me. Make of that what you will.
March 19, 2010 @ 3:57 pm
When people talk about taking coconut oil alongside D3, what is the ratio of oil:IU’s – e.g, how much oil would be taken with 5,000 IU’s dose?
March 19, 2010 @ 7:08 pm
@ Brian, no 9: I have also heard this and take my vitamin D with fat as well. I met an older woman 2 years ago who has been afraid of fat most of her life and she now has osteoporosis. Her doctor told her to take D3, but after a year she saw very little results. I have now “cured” her from being afraid of fat and she takes her D3 with some coconutoil mixed in warm water every morning. She was excited some weeks ago because the doctor checked her and said her bone strength had increased by 10% in a year! She has of course seen a lot of other health results as well by using butter etc on a daily basis.
March 19, 2010 @ 10:05 pm
Clearly there is a lot more experimentation needed in this area, but this article is a useful start. Here are three possible experiments:
1. comparison of the effect of taking normal vitamin-D tablets with “food-state” tablets (such as sold by Finlandia Pharmacy in Vancouver), and with vitamin-D spray as sold by Mercola.com;
2. an experiment designed to determine if other supplemental minerals such as calcium and magnesium are better absorbed if they are taken with vitamin D. If this is so and supplements are being taken with two main meals (e.g., breakfast and supper), might not it make sense to take some vitamin D in the morning also, even if total absorption of vitamin D might be slightly reduced? If most of the calcium and magnesium are being taken in the evening for improved sleep, wouldn’t it make sense then to take most of the vitamin D with the evening meal, leaving some for the morning for the other supplements and perhaps a small amount of calcium and magnesium then?
3. comparison of the effect of taking vitamin D in the morning or evening, with an equally large meal.
March 20, 2010 @ 12:31 am
I’d say post workout… as I argue for in point 3 here:
http://www.eatmoveimprove.com/2009/10/a-closer-look-at-vitamin-d/
Of course, you shouldn’t workout at least a couple hours or more before bed because that can screw up your sleep as well.
Something to think about.
March 22, 2010 @ 3:24 am
On the subject of Vit D and sleep. My best guess is that anybody experiencing sleep problems while taking vit D in the evening are likely to be magnesium deficient. Magnesium and vit D work together. High intakes of vit d are likely to unmask a serios lack of Magnesium which is regarded as a sedetive mineral alongside calcium and zinc.
Have noted this in a few of my patients on vit D supplements.
March 22, 2010 @ 2:35 pm
I wonder how long these high dose forms of vit D3, and all the other supplements will last if the EU food supplements directive goes through. This directive will restrict many items freely sold at present, because there is little clinical trial evidence that they work. Not only will this cover vitamins but many mineral supplements as well eg. selenium at 200microgram tabs zinc etc.etc.
Come on Dr B, I’ve mentioned this before…you are one of those who embrace what is depricatingly called ‘alternative ‘medicine’. You ought to be supporting our freedom to choose what we take and how much!!! but perhaps you do, but very quietly!
Please read the bumff on this and contact your MP to get these proposals stopped.
There is a (was) a PM’s petition available to sign, but sorry dont know the web address.
March 24, 2010 @ 1:52 am
Recent study in the BMJ involving half a million people showed those with highest vit d show 40% reduction in colon cancer risk. Can we ignore studies like this? At your peril.
So Peter to suggest there is no evidence that vit d is not effective is based on being poorly informed.
March 25, 2010 @ 4:33 pm
My lab only measures 1,25 OH vitamin D, which I understand is not as desirable as measuring 25 OH vitamin D. Still, is it good enough for practical purposes? Is my own level of 36 picograms/milliliter likely to be adequate? That was my level after two months of taking 4,000 units of D3 daily. The lab’s reference range is 18-72. I am old, get little sun, and probably not much D from food.
March 26, 2010 @ 8:50 pm
The only reason i found this website and thread was because last night i happened to take a vitamin D tablet (don’t normally take them) and this morning i woke up feeling as though I imagine how you might feel if you’ve taken a sleeping tablet. Very groggy and very tired. Normally, even if I haven’t slept I still feel wide awake very quickly. That prompted me to google vitamin D and sleep, hence how I wound up here. So i don’t know if that contributes to this thread. Could be a coincidence. I did sleep, had loads of dreams too though I wouldn’t say I had a ‘good’ sleep as such. Recently I haven’t been sleeping at all. I probably feel slightly worse than if I hadn’t slept at all.
March 29, 2010 @ 10:50 am
I have been taking 20000 IU daily for the last two weeks. It has been life changing. My arthritis has been really bad since I was 26 (am not 44) and I spent years on crutches and even in a wheelchair at one point. Last week I jogged 12 miles. No kidding. Have not been able to do this in 18 years. No swollen knees and hardly any pain. Backpain is reduced by 80%. Psoriasis is receeding. I had breastcancer 5 years ago as well so it appears I tick a lot of boxes for vitamin D deficiency.
Everybody around me has a bad cold at the moment. Not me, not this time. I am usually the first one to go down with anything.
My mood has lifted (suffer from SAD as well) to really high levels. I actually wake up felling happy. Don’t even care if it rains.
It only took 2 days of vitamin D3 before I noticed a really big change.
As for the sleeping bit, I don’t sleep very well if I take half my dose around 2100. I am restless during the night and I wake up very early. Not tired though. Oddly enough. Still fresh as a daisy after only 6 hours of sleep (this would normally kill me). I think I will start taking my pills in morning and see how that works. Been going to bed around 1 am as I haven’t felt tired at all.
March 30, 2010 @ 1:04 pm