Vitamin A is an extremely important nutrient obtained from food and recent evidence suggests that its absence could lead to diabetes.
Vitamin A is found in all sorts of foods but for some it would appear that not enough of this nutrient leads to a higher susceptibility to diabetes. It is mostly found in fish oils, liver and many fruits and vegetables.
Diabetes is a highly debilitating disease and it is currently estimated that 29 million people in the USA alone have to suffer its consequences. If high blood sugar levels are not reduced or managed then a number of diseases such as loss of sight through diabetic retinopathy with kidney disease (nephropathy) develops leading to amputation of limbs and cardiovascular problems.
Most of these diabetes cases, in fact nearly 95% are type 2. It occurs when the beta cells of the pancreas fail to produce insulin which is the hormone regulating blood glucose levels. This occurs when the beta cells have been destroyed by the body’s immune system. Sometimes the body simply cannot make use of the insulin which is type 1 diabetes. Research on vitamin A binding to beta cells has recently been conducted in both the United Kingdom and Sweden using mice and reported in the Endocrine Journal. The team found a specific type of vitamin A binding receptor which is a G-protein coupled receptor type C5C or GPRC5C as it is more commonly known. Albert Salehi, senior researcher at the Lund University Diabetes Centre in Malmo, Sweden reported that inhibiting or blocking these vitamin A receptors in beta-cells significantly reduced section of insulin. The beta-cells also appeared to be protected from severe inflammation in the presence of vitamin A. If vitamin A was completely deficient then these beta-cells died completely.
The research looked at beta cells from people with and without type 2 diabetes . They found that when the GPRC5C receptors in these cells were even partially blocked , the addition of sugar meant their insulin-secreting action reduced 30%.
The researchers believe that drugs which activate the GPRC5C should be identified which mimic vitamin A. It has to be remembered that too much vitamin A is harmful.