Scratch,
I'm sure you're aware that Thiamine (B1) is just one of many important nutrients. I've read in many places that a B-complex including B1, B3, B6 and B9 are important for optimal nutrition for anybody, especially for diabetics.
You may also be aware of strong recommendations to acquire these nutrients as far as possible from natural food sources. Supplementation can be beneficial above and beyond what can be acquired through healthy eating. It can be difficult to track and sort out how much of each of the various nutrients we get from our diet. Still more difficult when we take the good advice to eat a varied diet. I'm rather convinced though from what I've learned that we want to start with nutrients from foods FIRST, then, if needed supplement.
Further, I concur with the suggestion that synergies between various nutrients including these vitamins, other vitamins, minerals and phytochemicals (many of these synergies still poorly understood) are important and so best obtained in their natural form. That is, whole fresh foods, not processed or fortified concoctions.
This list:
[USDA National Nutrient Database for Standard Reference, Release 18, Content of Selected Foods per Common Measure, Thiamin mg sorted by nutrient content] and
others like it can help you find natural food sources for specific nutrients that you're interested in. You have to sort through listings of prepared foods too but even those can be helpful at times.
Making my way down this list of B1 sources I find whole wheat TOTAL cereal at #2. This is one rare example of a prepared food that I do eat fairly regularly. Then raw oat bran is the next thing on the list that I might add to my diet. Now skipping a lot of prepared foods and foods that are obviously not diabetic friendly (no wonder we have greater need right?), and meats (I'm vegetarian). Finally I start finding things like buckwheat flour, soy beans, peas, other beans... you get the idea. If you study the list you may notice that raw things have more, and cooked have less. This and other vitamins are clearly lost in cooking. So I lean toward raw and keep heat and duration to a minimum when I do cook for just this reason.
