University of California : Moores UCSD Cancer Center study links vitamin D, type 1 diabetes

Global view supports concept of using vitamin D in reducing disease risks
Sun exposure and vitamin D levels may play a strong role in risk of type 1 diabetes in children, according to new findings by researchers at the Moores Cancer Center at University of California, San Diego (UCSD) and the Department of Family and Preventive Medicine. This association comes on the heels of similar research findings by this same group regarding vitamin D levels and several major cancers.
In this new study, the researchers found that populations living at or near the equator, where there is abundant sunshine (and ultraviolet B irradiance) have low incidence rates of type 1 diabetes. Conversely, populations at higher latitudes, where available sunlight is scarcer, have higher incidence rates. These findings add new support to the concept of a role of vitamin D in reducing risk of this disease.
Ultraviolet B (UVB) exposure triggers photosynthesis of vitamin D3 in the skin. This form of vitamin D also is available through diet and supplements.
"This is the first study, to our knowledge, to show that higher serum levels of vitamin D are associated with reduced incidence rates of type 1 diabetes worldwide," said Cedric F. Garland, Dr. P.H., professor of Family and Preventive Medicine in the UCSD School of Medicine, and member of the Moores UCSD Cancer Center.
The study is published June 5 in the online version of the scientific journal Diabetologia.
Type 1 diabetes is the second most common chronic disease in children, second only to asthma. Every day, 1.5 million Americans deal with type 1 diabetes and its complications. About 15,000 new cases are diagnosed in the United States each year, where this disease is the main cause of blindness in young and middle-aged adults and is among the top reasons for kidney failure and transplants in youth and midlife.
"This research suggests that childhood type 1 diabetes may be preventable with a modest intake of vitamin D3 (1000 IU/day) for children, ideally with 5 to 10 minutes of sunlight around noontime, when good weather allows," said Garland. "Infants less than a year old should not be given more than 400 IU per day without consulting a doctor. Hats and dark glasses are a good idea to wear when in the sun at any age, and can be used if the child will tolerate them."
The association of UVB irradiance to incidence of type 1 diabetes remained strong even after the researchers accounted for per capita healthcare expenditure. This was an important consideration because regions located near the equator tend to have lower per capita healthcare expenditures, which could result in under-reporting of type 1 diabetes.
The researchers created a graph with a vertical axis for diabetes incidence rates, and a horizontal axis for latitude. The latitudes range from -60 for the southern hemisphere, to zero for the equator, to +70 for the northern hemisphere. They then plotted incidence rates for 51 regions according to latitude. The resulting chart was a parabolic curve that looks like a smile.
In the paper the researchers call for public health action to address widespread vitamin D inadequacy in U.S. children.
"This study presents strong epidemiological evidence to suggest that we may be able to prevent new cases of type 1 diabetes," said Garland. "By preventing this disease, we would prevent its many devastating consequences."
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This is the fifth environmental paper from this research team to show a strong association between vitamin D and various major diseases using global incidence data. The previous four were related to cancer incidence, the first of which illuminated a similar pattern for kidney cancer, published Sept. 15, 2006, in the International Journal of Cancer. The second, on ovarian cancer, was published Oct. 31, 2006, in the American Journal of Preventive Medicine. The third, on endometrial cancer, was published Sept. 16, 2007, in Preventive Medicine. The fourth, on breast cancer, was published in the May-June 2008 issue of The Breast Journal.
Authors on the diabetes study are Sharif B. Mohr, M.P.H., Cedric F. Garland, Dr. P.H., Frank C. Garland, Ph.D., and Edward D. Gorham, Ph.D. of the UCSD Department of Family and Preventive Medicine and Moores UCSD Cancer Center.

vitamin D insufficiency in pediatric patients with low bone density

Study published in Pediatrics suggests examining vitamin D status in patients with history of fractures or low bone density
Vitamin D insufficiency is common in adults and is emerging in the world of pediatrics. A mild degree of vitamin D deficiency, also known as vitamin D insufficiency, causes rickets in children and can be treated with increased amount of nutritional vitamin D intake as well as increased sun exposure.
A new study conducted by physicians and researchers at Nationwide Children's Hospital, is the first study to investigate vitamin D insufficiency in pediatric patients with low bone density.
According to the study, published in the June issue of Pediatrics, among the 85 patients studied, 80 percent had a vitamin D insufficiency. All the patients had a history of bone fragility or underlying chronic medical conditions that put them at a risk of osteoporosis, which is not just an adult disease, but is seen in children and can originate during childhood. Vitamin D insufficiency may contribute to low bone mass or even make the underlying metabolic bone disease worsen if not treated. Vitamin D is essential in bone growth and mineralization in children and adults.
The study's lead author, Sasigarn Bowden, MD, a pediatric endocrinologist and attending physician in the Metabolic Bone Clinic at Nationwide Children's explains, "We need to check vitamin D levels in all patients with history of multiple fractures or low bone density and treat the vitamin D problem if the levels are low. The supplementation of vitamin D should be a priority in the management of pediatric patients with osteoporosis or osteopenia in order to optimize their bone health and potentially prevent fractures."
Potential factors that may account for vitamin D insufficiency in various chronic medical conditions include low vitamin D intake and decreased sun exposure. Four studies in Europe found that 80 percent of healthy children and adolescents had insufficient vitamin D levels in the winter.
"Due to the number of recent studies of healthy children or adolescents with a high prevalence of vitamin D insufficiency, the public should be aware of the fact that it is common, especially living in high altitude," said Bowden, also an assistant professor of Pediatrics at The Ohio State University College of Medicine. "Sometimes our vitamin D levels get low at the end of winter due to less exposure to sunlight, but if we take a multivitamin D supplement, or consume an adequate amount of vitamin D from dietary sources such as vitamin D fortified milk or orange juice, we should be okay throughout the entire year."
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