Studies have shown that a sensible amount of sunlight reduces our risk of several serious health conditions. So are healthy vitamin D levels associated with significantly lower risks of most forms of cancer, as well as heart disease, autoimmune diseases and infectious diseases. You can get Vitamin D from your diet – oily fish, such as salmon and tuna is a good source, as is margarine, milk, eggs and fortified breakfast cereals. However, regular exposure to sunlight is the body’s natural, intended, by far most efficient and reliable source of Vitamin D. It is estimated that humans get around 90% of their Vitamin D from exposing their skin to UV light.
Dr. Reinhold Vieth, Associate professor at the Mount Sinai Hospital, Toronto, Ontario.

Vitamin D deficiency worsens the symptoms of Crohn’s disease and of ulcerative colitis, both IBD diseases.
Dr. M.T. Cantorna, Pennsylvania State University, Wisconsin.

Vitamin D deficiency has been associated with insulin deficiency and insulin resistance. In fact it was shown that Vitamin D deficiency is likely to be a major factor contributing to the onset of type I diabetes in children.
J.R. Ortlepp, J. Lauscher, R. Hoffmann, Medical Clinic I, University Hospital of Aachen, Aachen, Germany

A deficiency in Vitamin D is also thought to contribute to Type II diabetes, according to a recent study.
Dr. Barbara Boucher, St. Bartholomew’s and The Royal London Hospitals, London, United Kingdom.

Multiple Sclerosis (MS) is a disease of the central nervous system, leading to tremors and even paralysis. The cause is not known, but scientists have noted that exposure to sunlight during childhood appears to dramatically reduce the risk of developing this disease in later life.
Dr. Jeri Nieves et al, Mailman School of Public Health, Columbia University, New York.

Scientists have also noted that the incidence of MS is lower in sunnier countries.
Dr. J.G. McLeod et al, Department of Medicine, University of Sydney, Australia.

Vitamin D is a prerequisite for the absorption of calcium and other minerals from our diet. In a controlled study, the group receiving UV light absorbed 40% more calcium from their diet than their counterparts who did not receive any UV light.
J.A. Maclaughlin et al, Boston University School of Medicine, Boston, Massachusetts.

Bone diseases such as osteoporosis and osteomalacia are linked to vitamin D deprivation.
Dr. M.F. Holick, PhD, MD, Boston University School of Medicine, Boston, Massachusetts.

Sunlight can even help to keep your teeth strong. A dental study in the United Kingdom found that the prevalence of cavities was greater in children from Scotland, the North-West, Wales and Merseyside – areas with less than average sunshine. The proportion of 12-year-olds with untreated cavities was three times greater in Schotland than in the South West Thames region.
M.D. Downer, Eastman Dental Institute for Oral Health Care Sciences, University of London, United Kingdom.

Vitamin D deficiency is also associated with increased cardiovascular risk, above and beyond established cardiovascular risk factors. The higher the risk associated with vitamin D deficiency was particularly evident among individuals with high blood pressure.
Thomas J. Wang, M.D., Assistant professor of Medicine, Harvard Medical School, Boston, Massachusetts.

A study in the British Medical Journal showed that people in the UK are more likely to die of heart disease in winter than in summer, which is believed to be because of low levels of Vitamin D.
S.J. Mayor, London, United Kingdom.

Cholesterol levels also rise in winter according to reports in medical magazine ‘The Lancet’, this is because our Vitamin D levels decrease in winter season.
S.G. Rostand, University of Alabama, Birmingham, Alabama.

Sunshine boosts levels of serotonin – the body’s natural happy hormone. That is why we tend to feel happier and more energetic when the sun shines. Regular sun can slave off moderate depression and Seasonal Affective Disorder (SAD) – also called Winter Blues – which is a depression specifically caused by lack of sunlight. Exposure to natural sunlight is beneficial, particularly if combined with exercise, such as a walk in the park.

Bright light treatment results in a statistically significant reduction in depression. Bright light does help severely depressed people feel better, and it works faster than a standard treatment of drugs or psychotherapy.
Dr. Daniel F. Kripke, Professor of Psychiatry at the University of California, San Diego.

Higher levels of serotonin in our bodies not only make us feel happier, but it also suppresses the appetite. This causes most people to eat less in warmer weather. Research has proven that farm animals living outdoors do not fatten as easily as those living indoors. This has also been confirmed by studies in which animals exposed to UV light lose weight. This effect is thought to be caused by the fact that UV light stimulates the thyroid gland, which increases our metabolism and thus burns our calories.
L. Lohmeier, PhD, Mississippi State University, Mississippi.

Although overexposure to the sun increases your risk of skin cancer, Vitamin D provided by sunlight can actually help to significantly reduce your risk of other types of cancer. A study carried out by the US National Cancer Institute found that people exposed to high levels of sunlight were significantly less likely to die from breast and colon cancer. A similar effect was seen in bladder, womb, esophagus and stomach cancer.
L. Helman, M.D. Scientific Director for Clinical Research, National Cancer Institute, USA.

A study comparing the health habits of 133 breast cancer patients with women who did not have the disease found that exposure to sunlight lowered the risk of breast cancer with 30 to 40% or more. In reaction to sunlight exposure, the body manufactures Vitamin D, which is thought to confer the protective effect.
Richard Harkness, Pharmacist and author of the book ‘Reducing Cancer Risk.

Responsible tanning makes muscles more flexible and eases stiffness. It works as a pain reliever in case of rheumatism, arthritis and muscular pain.
Dr. H. J. van der Rhee, dr. E. de Vries of the Erasmus Medisch Centrum, Rotterdam, The Netherlands

UV light can be used as an effective treatment for skin disorders, like psoriasis, certain allergy types and acne. The National Psoriasis Foundation reports that 80% of the people suffering from this condition improve when exposed to UV light.*
L. Lohmeier, PhD, Mississippi State University, Mississippi.