The dwindling daylight hours that inevitably come at this time of year are usually viewed with some dread by sufferers of Seasonal Affective Disorder (SAD) - a condition in which a shortage of sun can provoke anything from dark moods to full-blown depression. In addition to the light relief offered by increased exposure to the sun or sunlight-simulating devices, those afflicted may also be advised to take conventional antidepressants. Now that Prozac has been found in the mains water supply, I'm wondering whether some sufferers of SAD may be happy to be getting Britain's favourite antidepressant on tap.
If you're looking to lighten your mood more naturally during the darker months, you might be interested in research indicating that SAD may respond to a nutritional approach. One effect of the sun's rays is to stimulate the production of vitamin D in the skin; recent research suggests that it has important roles to play in the brain, leading scientists to test whether supplementing with vitamin D might help lift the symptoms of SAD. Just five days of treatment with vitamin D (at a dose of 400 or 800 international units - IU - per day) was found to improve winter mood.
In another piece of research, the mood of SAD sufferers improved more in individuals treated with a single dose of 100,000 IU of vitamin D than in those treated with light therapy. Further evidence for vitamin D's potential came from research published earlier this year. In this study, individuals were treated with 600 or 4,000 IU of vitamin D each day for at least six months. Both dosages led to improvements in the participants' mood and well-being, with those on the higher dose benefiting the most.
This research may have particular relevance to Britons, as a quarter of us suffer from vitamin D deficiency in the winter. Useful quantities are found in prawns and oily fish such as sardines, mackerel and salmon. Those with a tendency to winter depression may do well to have their vitamin D levels assessed.
SAD sufferers with low levels of vitamin D may benefit from supplementing with cod liver oil, as each teaspoon contains about 400 IU of vitamin D. I recommend taking 1 or 2 tsp throughout the winter. Larger doses should be taken under medical supervision. Those preferring to supplement with vitamin D itself should be aware that it comes in two main forms: cholecalciferol (also known as vitamin D3) and ergocalciferol (vitamin D2). Cholecalciferol is the more potent and preferred form of vitamin D. Ensuring a good intake of this nutrient may help keep those prone to SAD from suffering a winter of discontent.
Dear John
Do you know anything that may help stop my gums bleeding? Every time I brush I seem to lose quite a lot of blood, and this is causing me some concern. My dentist says I do not have gum disease.
Fiona Weston
Excessive bleeding from the gums can, very rarely, be the sign of a problem with the clotting ability of the blood. If this has not been checked already, I recommend you have a blood test for this to be on the safe side. A much more common cause of bleeding gums in which there appears to be no actual disease is a degree of fragility in the smallest blood vessels, the capillaries. If you also find that you bruise easily, then suspect capillary fragility.
Capillaries can be strengthened with vitamin C and plant substances known as bioflavonoids. These are found in many fruits and vegetables, particularly in the pith of citrus fruits. You may benefit from eating one or more whole citrus fruits each day, and you could also take a supplement that contains vitamin C and bioflavonoids. I suggest you take this at a dose of 1g, once or twice a day.
If you have any issues you would like Dr Briffa to address in his column, please email him on john.briffa@observer.co.uk. Please note that Dr Briffa cannot enter into any correspondence. You can also visit drbriffa.com. Before following any recommendations in this column, you should consult your own medical adviser about any medical problems or special health conditions
Nutrition news
In recent years there has been growing interest in the role a substance called homocysteine plays in several conditions, including cardiovascular diseases such as heart disease and stroke. Specific nutrients, including vitamin B6 and folate, have homocysteine-lowering ability and are believed to help prevent cardiovascular disease. Recent evidence suggests that vitamin B6 has the capacity to temper the levels of other substances believed to increase heart disease risk, including C-Reactive Protein (CRP) and fibrinogen. In a study published recently in the European Journal of Nutrition, Italian scientists assessed the relationship between levels of folate and B6 in the diet and risk of heart attack. Compared to individuals consuming low levels of folate and B6, those consuming high levels of both of these nutrients had a 71 per cent reduced risk of heart attack. Good sources of folate include green leafy vegetables and oranges, and B6 can be found in food such as bananas, lentils and liver. You may gain additional protection from heart disease by taking a B-complex supplement, containing about 400mcg of folic acid and 25mg of vitamin B6, each day.
