A European study found that there was a peak in cases of Type 1 diabetes annually during winter and spring. Finland has one of the highest rates of Type 1 diabetes in Europe, which is assumed to be a result of reduced exposure to UVB radiation. From 1965 to 2005 the incidence of Type 1 diabetes increased dramatically in Finland. During this same period, vitamin D3 intake decreased from 4,500 IU a day to 400 IU a day based on the recommendations of the medical establishment.

Another interesting study found that supplying children with at least 2,000 IU of vitamin D3 per day (compared to less) resulted in 90 percent lower risk of developing Type 1 diabetes by age 31.

Type 1 diabetes (also called juvenile diabetes) is a terrible, life-altering disease. In many cases, the cause is early exposure to cow’s milk, which causes an autoimmune attack on the insulin-producing beta cells in the pancreas. Vitamin D3 inhibits this destructive immune reaction.

A carefully conducted case-controlled study of service members in the United States found that those with vitamin D3 levels of less than 14 ng/mL had 3.5 times higher risk of developing Type 1 diabetes than those who had vitamin D3 levels of 40 ng/mL or higher.

Another large study found that both insulin resistance and fasting insulin levels were inversely associated with a person’s serum vitamin D3 level.

Vitamin D3 deficiency and insufficiency are also linked to a higher incidence of Type 2 diabetes.

Supplementing with vitamin D3 has been shown to improve insulin resistance, thus improving glucose control in Type 2 diabetics.