Vitamin D is an essential nutrient which contributes to, amongst other things, healthy and strong bones and helps to control the amount of calcium in the blood. Obtaining sufficient Vitamin D from a healthy diet can prove difficult with around only 10% being found naturally in food. Foods which do contain Vitamin D include oily fish, eggs and mushrooms. Some other foods are fortified with added Vitamin D, such as some cereals and orange juice, and more recently some manufacturers of bread have begun to supplement their loaves with the vitamin.
The majority of Vitamin D your body receives however is created via UVB radiation from the sun hitting exposed skin, and indeed Vitamin D is commonly referred to as the Sunshine Vitamin. Demands of modern life, combined with low levels of sunlight in countries such as the UK, means that during the shorter, darker winter days many rely on Vitamin D stores built up during the summer months between May-September. A fair skinned individual may only require as little as 5-10 minutes of unprotected sun exposure a few times a week during the summer to create sufficient Vitamin D, but many do not achieve even this. This could be due to a fear of contracting skin cancer and the message to use sunscreen at all times. However, dependent on your colouring, even a relatively a short burst of sun exposure around the middle of the day (certainly not long enough to burn), three days a week on unprotected skin on your arms, shoulders, trunk and legs, should be sufficient. Children will require even less time, only a few minutes of unprotected sun exposure.
Vitamin D is known to activate the genes which release dopamine and serotonin, a lack of which is commonly linked to depression. Lack of Vitamin D can cause low oestrogen levels in women and reduced testosterone levels in men, both of which can impact on mood. How often have you heard of people affected by SAD (Seasonal Affective Disorder) during the winter months?
Around 10 million people in the UK are thought to have low Vitamin D levels and could be at risk of health problems. People with darker skins are particularly at risk (such as those from an African, Afro-Caribbean or Asian background), as well as infants and children, pregnant women, the over 65’s, those classified as obese or who may have undergone gastric bypass surgery and people who are housebound. Vitamin D deficiency is not just a problem in the UK, as it has been discovered that some of the population of India, Qatar and the Gambia also have low Vitamin D levels, probably due to local dress codes where even men cover their whole body from head to toe due to cultural reasons.
Research has found that older people who have insufficient Vitamin D are more likely to develop dementia, slow mental decline and Alzheimer’s. However, further studies are required to determine if supplementation can prevent such conditions altogether. Further studies have shown an overwhelming body of evidence linking a lack of Vitamin D with a range of illnesses, diseases and conditions, such as diabetes, rheumatoid arthritis, multiple sclerosis as well as osteoporosis and rickets in children, cases of which have risen in recent years. Increasing the level of Vitamin D in individuals has been shown to lift depression, boost recovery times of those undergoing chemotherapy, improve psoriasis and even increase the effectiveness of IVF.
Some drugs such as laxatives, steroids, anti-seizure and anti-cholesterol medication however can restrict the amount of Vitamin D absorbed. It is always best to speak with your Clinician about supplementing your diet if you take these medications, as they can test your levels and prescribe adequate supplementation. NICE (the National Institute for Health and Care Excellence) recommends doctors and other health workers discuss and record a patient’s Vitamin D intake in those groups who may be at risk. NICE even encourages local authorities to provide supplementation free of charge to children.