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