High Dose Vitamin D Therapy for Seasonal Affective Disorder (S.A.D.)

Posted by: Maff


As part of my illness I have suffered greatly with Seasonal Affective Disorder, known also by its appropriate acronym - SAD. I notice large seasonal variations in my mood, energy levels and other symptoms and also day to day variations depending on the weather. Even a cloudy or rainy day in summer can make me feel depressed and sluggish.

I have recently tried high dose vitamin D treatment after seeing studies that showed very positive results and wanted to tell you about what it has done for me. First though I want to talk a bit about my experience with SAD.

There was a time before I knew about SAD and realised I had it when I felt suicidal each year from October to March. All I felt was total despair and spent most of my time in bed. If I hadn't still been living at home with my parents I wouldn't have been able to cope and who knows what would have happened. As it was I stubbornly fought a mental battle against thoughts of ending my life and managed to pull through.

 Thankfully after a few years I saw the pattern and realised what was going on. The first treatment I heard about for SAD was bright light therapy. This is usually one of the first treatments recommended by doctors (along with antidepressant medication) and involves sitting in front of a special 'light box' for a certain period of time each day, usually 30 minutes to 2 hours depending on the light box and severity of the patient's symptoms. Light boxes are designed to provide light bright enough to mimic the effects the sun has on the body; namely suppressing production of the sleep hormone melatonin and stimulating production of the mood enhancing neurotransmitter serotonin (along with a number of others).


» Learn more about SAD light boxes


Unfortunately for me, although studies suggest light boxes are very effective as a treatment for SAD and I heard many sufferers recommening them, they did little to reduce my symptoms. I experienced a moderate energizing effect but my mood was still very low.

The first thing that really made a difference for me  was the simple measure of waking up earlier in winter. My sleep pattern had been to go to bed about 2-3am and wake up at 12-1pm (a shift common in ME/CFS, SAD and other environmental illnesses). One year as October approached I began going to bed between 11pm and midnight and waking up at 9am. The difference this made to my mood was astonishing. Although during that winter there was still a noticeable difference to how I felt in summer I no longer felt the heavy weight of despair and didn't have a single suicidal thought. Further to this getting outside during daylight hours in winter and letting the suns rays directly enter the eye also made a positive difference.

So if you suffer from SAD and spend your days in bed asleep or with the curtains closed try waking up earlier and getting outside as much as possible. Like me you may be amazed by how much your mood improves.

Now on to vitamin D. The sun not only affects the physiology of our bodies (and our mood) by the action of bright light hitting the retina of the eye but also by triggering the production of vitamin D in the skin as its rays strike uncovered areas. You may be surprised to learn that "vitamin D" is actually not a vitamin at all; its active form is actually a form of steroid hormone. As a result it has powerful effects on the body beyond aiding in the absorption of calcium and prevention of osteoporosis for which it has traditionally been known. The thing that is important to SAD sufferers is that vitamin D is required for the production and activation of the mood elevating neurotransmitters serotonin, dopamine and noradrenaline/norepinephrine.

When exposed to certain wavelengths of UVB rays from the sun the skin produces vitamin D3 (cholecalciferol). This is the most active form and is also found in oily fish and animal products. Plants contain the vitamin D2 (ergocalciferol) form which is less well absorbed and utilised by the body. Vitamin D3 is also widely available in supplement form.

After seeing studies suggesting people low in vitamin D were more likely to develop depression and SAD and that vitamin D supplementation could alleviate the symptoms of SAD I began to suspect it would also benefit me. A few small studies had shown that doses of 800-2000iu per day were enough to help those with SAD so last winter I supplemented 2000iu every day but gained little benefit. However, I then came across research which used much higher doses - 100,000iu in one single dose.

I discussed using higher doses with my nutritionally orientated doctor and she said she had used doses of 25,000-50,000iu D3 per week with her ME/CFS and SAD patients with great success.  This works out at roughly 3500-7000iu per day. Vitamin D3 has been shown to be non-toxic at these levels and well tolerated as the body converts it to the active hormone (1,25-dihydroxycholecalciferol) in the liver and kidneys as needed.

I started with a 25,000iu dose and within hours the effects were obvious. My mood, even on an overcast day, was noticeably brighter. It was a strange sensation in that I felt as if it was summer even on a cloudy day in the depths of winter. I found this mood elevation lasted for 3-4 days before starting to really tail off. Taking 50,000iu lasted the maintained the improved mood for the whole week so I now intend to take this dose weekly during the winter.

So it seems I have found the missing piece of my SAD puzzle. The combination of getting as much sunlight as possible and taking high dose vitamin D3 is highly effective at relieving my symptoms and making me feel like I do during the summer months when the sun is doing all of the work.

If you suffer from SAD then I highly recommend you try adding vitamin D3 to your treatment regimen. It may be that 800-2000iu per day may be all you need in which case regular capsules of 1000iu from the healthfood store will be fine. These are very inexpensive. If you require higher doses like myself then getting the concentrated form and taking it weekly or every other week may be a better option. There are a few suppliers on the internet (no prescription required) or you may have to get it through your doctor.

SAD is a terrible thing to experience so I hope this information helps those of you who are suffering.

Here's to brighter and happier winters!


» More on SAD treatment and vitamin D





About: Matthew Hogg ("Maff")
Diagnosed with M.E./chronic fatigue syndrome aged only 11 years old and subsequently associated illnesses including irritable bowel syndrome (IBS) and multiple chemical sensitivity (MCS). Despite his own struggles he has constantly sought to educate and support others suffering from such "invisible illnesses" through his website, The Environmental Illness Resource. He fully recovered from MCS using his own approach and holds a Bachelor of Science Degree in Nutritional Health.



Comments (34)Add Comment
 1 2 > 
written by Alan Weber Heath Ohio, February 11, 2009
Thank you so much I have been taking only 1000 iu per day out of fear of toxicity. It has not worked very well for me I'll start at 4000 iu per day
written by Reiser, June 18, 2009
I noticed an effect within 24 hours of taking 10,000 IU. However, after a few days, I was very overstimulated and backed down to a smaller dose. Just wanted to note that for anybody else that might read this article.
written by Don Hoogeveen, October 14, 2009
I have a serious problem with SAD as well. Have coped with it through medications in the past. However, the medications have lost their efficacy as I have developed tolerance to them. I noticed that I was having the problem with medications last Spring and this Fall the problem is even worse.

Therefore, I happened upon your blog through google search on alternative treatments and it was not much of a decision to give D3 a chance. I have been using it for only two weeks, so I will report back my results at a later date in addition to this post.

I noticed a positive effect with 10,000 IU/day, but it too made me feel very stimulated, so I backed it down to 4,000 IU per day. That seemed to work well for the past two weeks. If fact, I felt almost normal which almost miraculous for me during this time of year. However, yesterday I was very anxious (bad stress headache, loss of sleep, etc.), so I am going to increase the dose to 10,000 IU's again and then plan to back down if the symptoms are under control.

I do have a couple of questions if you do not mind answering.

1. Your blog seems to imply you take your weekly D3 all in one shot. Is that the case and what advantages or disadvantages is there between weekly and daily dosages?

2. My symptoms seem worsen with the advent of weather changes in combination with the lack of sunlight from Fall through late Spring. Do you have a need to adjust your dosages throughout the Winter season as well?

Undecided if D3 will work longterm for me, but I will give it a "go" and report back.

written by Matthew Hogg, October 16, 2009
Hi lowegian,

I'm glad you have had some positive results with vitamin D3 so far. It was exactly the same for me. I took a dose of 25,000IU as I mentioned in my original article and I quickly felt a lot more "normal". It was as if it had suddenly changed from winter to summer.

I too have problems with overstimulation however. This is likely due to the fact that vitamin D3 increases both serotonin, which is involved (along with melatonin) with the mood changes associated with SAD, but also the catecholamine neurotransmitters (e.g. dopamine, noradrenaline). All of these are stimulatory neurotransmitters and can be too stimulating when levels are too high.

The trick as you can imagine then is to get the balance right and it sounds like you are attempting to do this at the moment. Hopefully you will find a dose that keeps the SAD at bay without causing side-effects due to stimulation. We must remember that nutritional supplements can have side-effects just as medications can/ Although certainly in my experience, vitamin D3 is a far more effective treatment for SAD than any SSRI or other antidepressant drug so is worth persevering with.

In answer to your questions....

1. Vitamin D is fat soluble which means the body stores it for use as needed. You therefore can take a large dose once a week and your body will store it and convert it to its active metabolites as and when this is required. This is in contrast to water soluble vitamins such as vitamin C which needs to be taken many times a day to maintain high blood levels as it is simply excreted in the urine if the body doesn't need it immediately. The advantage of taking vitamin D weekly is simply....that it's easier smilies/wink.gif

2. Yes, my symptoms worsen with weather changes as well and this seems to be a common feature of SAD. I notice it the most in summer actually. An overcast day in summer really drops my mood and motivation! In these cases I may take an extra couple thousand IUs that day for a boost.

I would be negligent if I didn't suggest you have your vitamin D levels checked at least once or twice throughout the winter if you are going to stay with this long-term. Hopefully your doctor would be receptive to the idea. There is good body of evidence for using vitamin D in SAD and other forms of depression so there shouldn't be a problem.

Do let us know how you get on and good luck smilies/smiley.gif
written by hAPPY DAYS, October 18, 2009
Being bed ridden from Fall to Spring sounds much more serious that SAD to me. It may well be the case that SAD is impacting upon an underlying depressive disorder, leading to a deeper depression than normal SAD might induce.
Also, try getting to bed by 10pm, at the latest, and rising at 6am (all year round), it makes a huge difference.
I do suffer from SAD and it took years to figure out what the issue was, but this is the first time I've considered using Vitamin D before winter kicks in, just as a precaution.
In the past I've tried St. Johns Wort, which can work for some.
But I have to say that meditation (Viapassana), 2 hours per day, morning and evening, works very effectively. My SAD symptoms disappeared as a result.
written by Matthew Hogg, October 18, 2009
Hi Happy Days,

You are correct, I don't just suffer from SAD....it is just another complication of my primary illness chronic fatigue syndrome (ME/CFS). And, yes I suffer depressive symptoms year round and problems with adrenal fatigue and underactive thyroid function - which all of course contributed to the severity of the symptoms I experienced as a result of SAD.

Having said that, depression is a serious illness and is certainly enough to keep sufferers in bed without any other medical conditions being a factor. SAD can be just as serious as severe major depression or other depressive disorders.

It's great to hear that meditation has worked so well for you. I too meditate daily (mantra meditation) and certainly find it helpful in lifting my mood (along with other benefits) but it is not enough alone for me. I feel the best approach to SAD includes the use of a number of therapies including waking as early as maintaining a sleep pattern to maximise natural light exposure, getting outside as much as possible, vitamin D, bright light therapy, negative air ionization, exercise (if possible), other nutritional and herbal remedies.....and meditation. There are no doubt more and the trick is finding what works for you but thankfully in most cases something will no matter how despairing you may feel.
written by Craig, January 07, 2010
Interesting stuff, this correlates with some research I found too by Dr Robert Young, who is now selling a D3 supplement with 50,000ui in one capsule

I ordered some from the United Kingdom stockist and I'm going to try it. I have CFS and IBS and I think also SAD.

Also started on Vitabiotics wellman today
written by Tracey Cardew, September 24, 2010
Hi Maff

I've suffered with SAD for about 10 years ago, and my normal winter routine is prophylactic anti-depressants from September to March (along with light therapy, exercise and fresh air). This works fairly well but I hate the side effects of the drugs.

I was really interested by your experience with Vit D3. I've been looking into this since hearing an article on the radio, and after reading your comments I decided to try using Vit D3 instead of my normal antidepressant therapy. From your info and other sources, I decided to start with 5,000 IUs a day. The impact was slight at first and so I increased to 10,000s daily.

Wow - what an effect. I've never felt so 'normal'. Even in the summer a dull day would get me down, but now that the nights are drawing in, I still feel energised and optimistic. I did notice that after about 3 weeks on the high dose I was having trouble sleeping, although this did not leave me feeling tired. Since then I'm taking alternate days of 5,000 and 10,000 units, and I'm considering a 'depot' dose of 50,000 units.

I just want to say thanks for sharing and I hope other sufferers are inspired to try this more natural therapy.

Thanks a million
written by Matthew Hogg, September 24, 2010
Hi Tracey,

Glad to hear you're having such good results with D3. My reaction after taking my first megadose was also "wow!". It's great to feel like your true self again isn't it!

I also experience overstimulation if I take to much and the 10,000 IU/day you have been taking is very high. Perhaps you would do just as well at around half of this and be able to sleep better. A normal sleep pattern is also important in SAD so it's all about getting the balance right smilies/wink.gif

Thanks for your positive comments and I hope you continue to enjoy bright sunshine-filled moods smilies/smiley.gif
written by Rae, November 01, 2010
Thank you Maff for so candidly sharing your experiences. You've helped me more than you can know smilies/cheesy.gif
written by Matthew Hogg, November 01, 2010
You're welcome Rae. If my experiences can help anyone I am happy to share!
written by Timo, November 03, 2010
Hi, i have a question, since you guys are having success, can you tell me what brand you use, as I am weary of different manufacturer's efficacy. Since early Oct I have been eating sugar, chocolate bars like a crazy man! I am thinking this is a side affect of SAD?
written by Matthew Hogg, November 03, 2010
Hi Timo,

Carbohydrate and sugar cravings are definitely associated with depression and SAD. Increasing blood glucose levels with these foods increases the transport of the amino acid tryptophan into the brain where it used used to synthesise serotonin - which improves mood. These cravings can therefore be seen as one way in which the body tries to restore normal serotonin levels. It's also worth noting that serotonin is the precursor for melatonin, the "sleep hormone", whose normal diurnal production is disrupted in SAD.

I obtained my vitamin D3 powder from my doctor and the tub is unfortunately unlabelled. Perhaps you can approach your doctor about using vitamin D3 as well. There is some good research to support its use. Take a look at the SAD Treatment page for some of these.

Good luck!
written by kirsten, November 09, 2010
Thank you so much for sharing this information. Over the last few years I've noticed a shift in my enthusiasm and hair loss around the month of October. I spent a year in Florida and noticed a huge difference in both areas. Less hair loss and definitely higher spirits.

I've since moved back to the East Coast (US) and am now experiencing the lack of motivation and increased hair loss again. I don't suffer from SAD but was diagnosed with a yeast overgrowth three years ago, so all that you wrote including the adrenal fatigue could be related to candida. Probiotics have helped with the yeast. I use Renew Life 50 Billion strains (for anyone who reads this and needs a good probiotic).

I've been researching hair loss and recently put two and two together about the season change, me not eating dairy, the decreased motivation and Vitamin D. I suspected the Vitamin D was a factor and your article confirms what I was thinking. God bless you for staying with us and sharing your experience to help others.

I will try the D3 and hopefully it will help to slow down/stop my hair loss and help regrow the areas that have thinned out.

One question: would cod liver oil be a good choice for someone who doesn't take gel caps?

All the best,
written by Andra, November 09, 2010
Hi, Thanks so much for sharing your story. I too feel at the mercy of the sunshine and weather all year round; it is some comfort to read that others experience the (for me) heavy weight of cloudy darkness, no matter the "season"!

I found your webpage doing a search for vitamin D and SAD, and had a specific question. Do you know about the effectiveness/safety of using Vit D2 instead of D3?

Two other ancillary questions:

*Is there a mobile friendly version of this website? I would love to explore it more, but can only access the internet via my phone. While I did manage to eventually get the article read and submit a comment, it too forever!

*Does anyone else object to the term SAD as I do? I use it, because it fits and people know it. But I do object to the acronym! It is SO MUCH more that "just" being sad! smilies/smiley.gif
written by Matthew Hogg, November 10, 2010
Kirsten - My problems are mainly yeast related as well and problems with the gut can have a huge impact on mood as they interfere with the absorption and metabolism of nutrients required for neurotransmitter and hormone synthesis and also create toxins that are absordbed and effectively poison the brain. These effects can also result in increased sensitivity to seasonal changes in my experience. Great to hear the probiotics help and that the extra sunlight in Florida did also. Cod liver oil might not be the best option as it contains a lot of vitamin A which can be toxic in high doses. It is possible to obtain vitamin D3 in powdered form so you might want to search for a supplier in the US. Sorry I can't give you a specific link (I obtain powdered vitamin D from my doctor here in the UK).

Andra - Basically D2 is the plant form of vitamin D, while D3 is the animal form and the same substance that is produced in the skin when exposed to sunlight...hence D3 is better utilised by the body and should therefore be the better supplemental form.
Great to hear you find this website useful. I am about to have the site re-designed and upgraded with new features. I suspect a mobile version would be complex and expensive to launch (I run the site effectively singlehandedly!) but I will certainly look into it.
SAD is about as apt as acronyms come but I do take your point about it trivialising the condition. It can be a lot worse than it sounds! Same with chronic fatigue syndrome from which I also suffer.
written by Belle, November 12, 2010
Hi Maff, thank you so much for sharing all this information with us. You know you cant seem to get dr's to help but people like you are a lifeline to so many of us.

Here's a tough one for you. I am a veggie, with two young children, have PMT and suffer from SAD. My doc keeps trying to put me on anti depressants. I tried them, and they made me feel calmer during my pmt, but i felt so tired and just wanted to sleep all the time. I have now been advised to take them a week before and during my cycle. Again i feel so tired and just want to sleep. This not practical at all with being a single mum of two.
Also sleep deprevated due to a 4 year child who wakes every 3-4 hours during the night.

I was really getting excited and was hoping that D3 was going to solve my problems, when i read that it is animal derived, oh no! I dont eat eggs or fish either. I have made appointment with my doc so was going to ask her for it, but what can i do now ?

Also would you know if Vitamin Bcomplex's help in this regard ?

Thank you again!!
written by Ronda, November 15, 2010
Hia Timo, I'm wondering if sugar cravings etc. junk food is from depression which can be caused by low thyroid. It's something I want to check out for myself and it's not from blood work. It's from taking one's underarm temp in the arm before getting out of bed and if it's low consistently finding a doc to prescribe either t3 or t4, whatever the doc thinks is right and finding that doct is the key.
written by Nina, December 11, 2010
Hi Maff, this is the first time I've come across your site - great information, thank you!
I've been a sufferer of SAD for as long as I can remember; I hate it when the Fall/Winter catalogs come out, it's an unpleasant reminder that months of dreary moods and lethargy are just around the corner. Silly, isn't it, how such a little thing is enough to trigger an adverse anticipatory response! smilies/wink.gif
I've been taking 1000 IU of Vit. D daily for the past year or so, strictly to offset the reduced sunlight of our Canadian winters ( I'm a B.C. resident ), but only recently wondered whether an increased dosage would have any positive effects on my mood and energy ( this is how I just discovered your site ).
After reading about your experiences, and going through the testimonials of your commenters, I'm certainly going to give it a shot! Thanks again ..... Nina.
written by Sascha, February 27, 2011

as Vitamin D is stored in the fat cells of the body, i've had the idea that possibly very skinny people might suffer more often from SAD than others. Are you people skinny? (I mean BMI around 20 or lower).
I am and I suffer from SAD. I will try experimenting with D3. My first 25.000 I.U. was kind of weird. Just like an emotional overflow andi didn't know whether to judge good or just strange. The next question is, if you are a skinny person, could it be better to use D3 more frequently than to use high doses? Or is the amoun of fat in the body irrelevant?

However it is, thank you for this thread!
 1 2 > 

Write comment
You can add your comment here