I don't know about in Holland, but in the U.S. many doctors are way behind the curve when it comes to preventive medicine. First, you must find a good, even excellent doctor. You must do what you need to do to learn, and begin to assume some responsibility for yourself, then you will KNOW if your doctor is up to snuff and can help beyond crisis management. Of course, someone who has had high blood sugar for a long time may have damaged their bodies to the degree that they will always need drugs to control it -- insulin shots at some point.
If blood sugar is out of control, then get medication to stabalize it. Then look for all the stuff you can find to help the medication out so if possible you can reduce the amount needed or even get away from it.
Stay away from not just refined carbs, but bad fats as well -- saturated and trans-fats. The good fats incude fish oil (Pharmaceutical Grade is best, but expensive), and high qualitity extra virgin olive oil. A few other oils are healthy too. Whole flax seed is better than flax seed oil. Make sure you get plenty of fiber in your diet, and the best fiber is soluble fiber, and the best of those has plenty of beta-d-gucans in it.
You may not have to worry about high-fructose corn surup in Holland, but in America it's in everything, and it's very bad for blood sugar, much worse than sugar and cannot be handled well by the body even after hard exercise.
Yes, r-ala is great, but even regular ala backed up with about 1 mg of biotin for every 200 - 300 mg of ala is good too.
There are a number of herbs that help including Cinnamon Extract (but many others help a little). Chromium at about 200 mcg a day reduces blood sugar in many by about 8%.
Recent studies have pointed to not just high-dose vitamin D3 is important, but also vitamin K2 (as opposed to regular vitamin K1) works in sychronicity with the D3 to regulate calcium in the body, and this is very important to people with Syndrome X or the pre-diabetic state now so common. Diabetes II is being investigated heavily as a screw up of the body's calcium metabolism. the combination of vitamin D3 (oil-based) and K2 (MK-7 form) keeps calcium away from where it should not be (on the artery walls or in bone spurs for example), and directs it where it should be (in the bones density and in the blood).
Beta-d-glucans are a topic in themselves, and something like avena sativa, which can have over 50% of the total weight be these wonderful glucans is very healthy for someone with high blood sugar. An it might be worth investigating the super health factor of the medicinal mushrooms out there including, reishi, shiitake, maitake, cordyceps, agaricus blazei, and turkey tail -- all of these range from high to very high in beta-d-glucans and they regulate (not stimulate) your immune system to a much better level than normal.
:gotsearch
To Wildfox, Yes, the D in cod liver oil counts.