As the nights draw in nourishing foods are crucial to preventing you from feeling SAD, Sally Duffin writes.

The clocks have gone back, it’s dark by teatime and the carved Halloween pumpkins are beginning to wilt. As we head on into winter months, the change in seasons can bring many unwelcome health conditions.

Seasonal Affective Disorder (SAD) affects around one in three people in the UK according to recent research. Symptoms include lethargy, anxiety, depression, irritability and the desire to both eat and sleep more.

Sufferers report that the onset of symptoms coincides with the darker, shorter days of winter and whilst the causes of the condition are not fully understood, the lack of sunlight is thought to trigger changes to our internal body clock and lead to a drop in serotonin and melatonin levels – two brain chemicals which regulate mood and sleep.

Another possible contributory cause to SAD is low levels of vitamin D. We can derive small amounts of vitamin D from foods (oily fish, eggs and butter are good sources) but we get the majority of it from the action of sunlight on our skin.

Suns’ rays trigger the manufacture of vitamin D in our bodies and the idea is that during the sunny summer months we can make enough vitamin D to last us through the dark cold winter. In practice though, here in the UK we do not get enough bright summer sunshine to do this and deficiency in vitamin D is widespread. During winter, supplementation of Vitamin D is a worthy consideration as even on bright days, the suns’ rays are not strong enough for us to make enough vitamin D.

As well as supporting healthy mood balance, vitamin D plays an important role in keeping our immune systems functioning properly. As the days turn colder and we spend more time indoors, we are prone to picking up cold viruses and various infections.

Alongside vitamin D, vitamin C vitamin A and the mineral zinc are crucial for immune health. Including plenty of fresh vegetables and fruits such as parsley, berries, watercress, sweet potatoes, carrots and peppers can provide vitamin C and beta-carotene (this converts to vitamin A in your body), whilst nuts, meats, fish and wholegrains give us zinc.

The old folk remedy of eating chicken soup to fend off a cold is a fantastic idea. Chicken is rich in protein and zinc and if you leave the bones in during cooking, many helpful nutrients leach out into the soup. Add a mixture of onions, garlic, carrots and mushrooms and you have a flu-fighting broth right there!

Herbal teas can soothe and comfort your body during a virus. Grated fresh ginger, a squeeze of lemon juice and ½ a teaspoon of good quality honey dissolved in hot (but not boiling) water is a highly effective blend for sore throats and coughs. Manuka honey is a particular type of honey prized for its antibacterial and immune strengthening properties and can be taken straight from the teaspoon to soothe a sore throat.

- Sally Duffin is a nutritional therapist and writer based in Holgate, York.