Insulin and Weight Gain

Insulin is a potent hormone that regulates glucose, fat, and protein metabolism. In many cases, people with type 2 diabetes start insulin therapy when oral medicines cannot or no longer control their glucose levels. This means that blood glucose levels in the body have been elevated for an extended period of time. In this state, the body does not metabolize glucose, fat, or protein in a well-regulated or efficient way. Cells that require glucose to function properly begin starving because of inadequate amounts of circulating insulin. Fat metabolism becomes abnormal, which can lead to high triglyceride levels. The body's metabolic rate then increases as it tries to convert this fat into a source of energy.
Both, type 1 diabetes and type 2 diabetes (diabetes mellitus) occur when the body can not produce or can not use the produced insulin. As a result you have to provide insulin to the body for diabetes cure and improve the symptoms of diabetes. But, there is a negative side of insulin as well. One such side effect is weight gain. The main work of insulin is to improve the ability of your body to use and store sugar (glucose). When your blood glucose levels are high, your kidneys try to remedy the situation by excreting glucose in your urine. Insulin provided from outside reverses these processes as blood glucose levels return to normal, which can contribute to weight gain.
To keep weight gain under control, you have to reduce your calorie intake and increase your physical activity. If you try to reduce your insulin dosage without changing your diet to control weight you may suffer from diabetes complications. Lowering your blood sugar with insulin or oral medications may lead to weight loss. But, it is suggested that you consult with a physician and keep regular exercise going to tackle weight gain caused by insulin.

Research: Taking Vitamin C with insulin stops blood vessel damage

For people with Type 1 diabetes with a history of poor glucose control, there is a very high chance of complications caused due to damage to blood vessels. These complications occur if the patients is suffering from a cardiovascular disease, or from diabetes. If this damage happens, some of the additional health problems include heart disease, reduced circulation, and amputation, kidney disease and diabetic retinopathy. In new research, it was found that taking Vitamin C with insulin can stop this blood vessel damage (link to article):

While neither therapy produced desired results when used alone, the combination of insulin to control blood sugar together with the use of Vitamin C, stopped blood vessel damage caused by the disease in patients with poor glucose control, said researchers.
nsulin and many other drugs have long been used to control blood sugar, but Ihnat - in an earlier project with scientists in Italy and Hungary - found that cells have a "memory" that causes damage to continue even when blood sugar is controlled. By adding antioxidants like Vitamin C, Ihnat found that cell "memory" disappeared and cell function and oxidation stress were normalized. "For patients with diabetes, this means simply getting their glucose under control is not enough. An antioxidant-based therapy combined with glucose control will give patients more of an advantage and lessen the chance of complications with diabetes," the expert added.

Of course, since this is research, and not yet a proven and stated scientific theory, this means that you cannot take this as treatment. However, if you are not getting enough Vitamin C in your diet, there is no problem with adding more Vitamin C.