Vitamin D is actually a hormone rather than, strictly speaking, a vitamin—one of the most powerful hormones in your body. It is active in quantities as small as one-trillionth of a gram.
Studies have shown vitamin D to have a protective effect against Type-1 diabetes. The results of a large pan-European trial, published in the journal Diabetologica in 1999, suggest that vitamin D supplements taken in infancy protect against, or arrest, the initiation of a process that can lead to insulin-dependent diabetes in later childhood. If this is the case, it seems reasonable to suggest that exposure to sunlight in early childhood may be important in preventing the onset of the disease.106 For adults, studies have shown that the lower your vitamin D level, the higher your blood glucose.107 One 20-minute full-body exposure to the summer sun will result in putting 20,000 IU into the body within 48 hours. However, if you are older, obese, or dark-skinned, you will get far less. In fact, using sunscreen of even a low SPF rating of 8 reduces vitamin D production by 95 percent.108 Dr. Robert Heany of Creighton University, one of the top vitamin D researchers, has stated that as many as 75 percent of the women in the United States are deficient.109
Just in case you are wondering about vitamin D levels and a raw vegan diet, researchers led by Luigi Fontana, MD, PhD, of Washington University110 looked at 18 men and women, ages 33 to 85, who had maintained a raw vegan lifestyle for an average of 3.6 years. They were compared with a matched group of 18 controls who ate a standard American diet containing animal fat and processed foods. The average vitamin D levels were higher in the raw vegan group than in the control group, despite an extremely low dietary intake of vitamin D—this may be indicative of the increased personal sun exposure.
If you live above 38 degrees north latitude (above Baltimore, St. Louis, Denver, and San Francisco), the sun is too weak from midfall through the following spring to stimulate significant vitamin D pro- duction. Other vitamin D absorption challenges are aging. As our skin becomes less efficient at producing vitamin D, excessive fat layers are found to inhibit production of vitamin D. The latter is a common con- cern for those of us who are healing obesity and diabetes.111 Therefore, from a holistic perspective, I advise 5,000 to 10,000 IU daily.
The benefits of sunlight or supplementation for adequate vitamin D levels do not stop with Type-1 and Type-2 diabetes but significantly affect the complications associated with a diabetogenic history and a Westernized diet and lifestyle. Research shows that vitamin D has a variety of important benefits besides lowering blood sugar. It seems to protect against 18 different kinds of cancers, has a significant positive impact on the immune system in fighting colds and flus, viruses, and TB, and protects against rickets and osteoporosis.