Fun in the sun

Clinical nutritionist Helena Oades says: 'Vitamin D from sunlight is very important for our bodies; to keep our bones healthy, as it is essential for calcium metabolism and also to support our immune systems. It can help regulate inflammation and insulin production.'

We feel happier
It is no coincidence that most of us feel much happier and more confident when the sun comes out, because sunlight contains serotonin (the body's happy chemical). However, for people who suffer from Seasonal Affective Disorder (SAD) it is more complex than this.

Levels of serotonin have been found to be lower in depressed people during the winter. It seems to affect younger people more than older people, and women are more likely to be diagnosed than men.

We feel more inclined to exercise
The onset of summer encourages us to exercise more. Leisurely walks in the sunshine suddenly become much more appealing. This is because of the serotonin produced by the sun, which makes us feel more energetic. Waking up to natural sunlight rather than artificial light also boosts your energy by encouraging positive thoughts from the moment you wake up.

Cholesterol levels are lower
There are fewer heart attacks during the summer, and cholesterol levels tend to be lower too. This is because of increased levels of vitamin D. UVB (ultraviolet) rays can also play a part in lowering blood pressure levels.

Aches and pains are reduced
Being out in the sun warms up our muscles and reduces stiffness. It can also ease the pain of inflammatory conditions such as chronic arthritis because of vitamin D.

It boosts fertility
The summer is a great time if you are looking to conceive. The sun lowers levels of melatonin, which reduces fertility. Sunlight can also make you more fertile, as well as increasing the amount of time for which you are fertile.

Research from Turkey has suggested that women who get less than one hour of direct sunlight each day can reach the menopause far sooner than those who get more sunlight. The sun also increases testosterone levels in men.

Gillian Lockworth, iVillage's resident fertility experts, says: 'There is no evidence that human beings are 'seasonal breeders' like sheep, although there is some seasonal variation in birth patterns. In addition, sperm counts are adversely affected by temperature and alcohol so men are slightly less fertile over the Christmas/New Year period because of the combination of parties and flu! Summer holidays often produce a 'blip' of births nine months later either because couples are more relaxed on holiday or less careful with their contraception.'

It boosts your immune system
The sun encourages your body to produce more white blood cells. These are your natural antibodies that fight infection and disease. Stress levels tend to be lower during the summer too, as we are more relaxed, and this can also help your body to fend off infection more easily.