Ben10 We were giving DS2 the omega3 supplements, but stopped taking them to see if any changes, and there weren't. So no point pushing him to take them. We don't give him any other supplements. DS2's diet I think is pretty varied:
rice krispies
cheerios
frosted flakes
sultana bran
toast
crumpets
bread/butter
egg mayo sandwiches (store bought egg mayo only, recognises homemade and won't touch it)
tuna mayo sandwiches (homemade only, won't touch storebought) 
bread rolls
tea cakes
bananas
apples
oranges
grapes
raisins
strawberries
peas (cooked, but spends half the time counting them)
carrots (raw)
sweet corn (rarely, usually more interested in counting kernels)
fish cakes
chicken nuggets
fish fingers
chips
roast potatoes
yorkshire puddings
crisps
quavers
spag bol
lasagna (sometimes)
sloppy joes (loose meat hamburger)
cold tuna pasta salad (rarely)
chocolate cake (no icing, will NEVER eat icing of any kind)
banana bread
gingerbread biscuits
rich tea biscuits
peanut butter cookies (occasionally)
oatmeal raisin biscuits
blueberry muffins
little cocktail sausages or pepperami (sometimes)
baked beans (sometimes)
chocolate
pretzels
I think that's it for the most part. He's much more fond of finger foods, as he struggles with a fork, although is pretty good with a spoon. By evening, he's usually so tired that he doesn't even want to USE a fork, so ends up getting some help or eating with his fingers. He is definitely a carb eater! Again, his diet isn't too restricted, but at the same time, we do get a bit tired of the same thing over and over, so tend to have an adult meal later in the evening a couple nights a week, or alternate nights we have stuff he may not eat or that is new, so that he has something he will eat every other night. It does make meal planning a challenge sometimes. He will not touch anything with a mushy or soup consistency, no sauces, no gravies, no spreads (like jam, nutella, marmite... only butter), no mustard or mayo (other than in tuna or egg mayo). He doesn't like the food to touch on the plate. And he doesn't like it getting all over his fingers (which is a bit odd considering he prefers finger foods). And the way the food is put on the plate can put him off as well. sigh. His best meal by far is breakfast.
We have a strict rule at the table - he has to eat 8 bites of his main meal. It used to be 6 bites, but we've recently moved it up to 8 now. We started doing that because he is so obsessed with counting and numbers that he would only eat if we counted it. 
Now that he is obsessed with laptop time, he only gets his laptop time after dinner in the evening, and only if he eats his 8 bites. If it's a new food, it's usually started out as a side dish along with his meal, and he's required to eat one bite of it, to try it.
We try to always have something available to him at every meal that he likes, such as bread/butter or raw carrots, but he has to take his bites of the main meal first or he'll only eat the things like bread/butter and ignore the rest. He will otherwise refuse to eat if pushed too hard. As long as he takes his required bites of food at the meal, he is allowed fruit for a snack later (generally an apple, as he eats 2-3 of them every day!).