It's a pretty good idea to take the following vitamins and supplements daily:
A calcium supplement, preferable calcium gluconate, with added Vitamin D.
A Potassium and Magnesium supplement;
4g of fish oil;
A good multivitamin;
The best sources of vitamins are food, but a multi will help if you have some spot deficiencies.
Vitamins which can be too low in some diets are Folate, some of the B vitamins, and of course we already mentioned D (which is fat soluble so care is
needed in consuming it).
Though food is the best source of these (mainly because of the ratios and proportions and the presence of co-factors, many of which we have yet to
discover), you also have to beware of one thing.
Cooking and storing foods causes their vitamin potency to decline. So even if your food intake is good, there are some reasons to also supplement.
One other caveat. Not all vitamins are created equal. Absorption, forms (like calcium carbonate vs the easier bioavailability of calcium gluconate),
lack of co-factors in a 'pill', and other things are all problematic. So stick with a recognized brand name.
Preferably, you want a brand that has an independent organization do quality and potency testing. Some brands my claim this, but you find they're
using in-house potency testing, so there's a tendency to, uh, massage the results.
Oh. One thing about taking vitamins. You have to find your own method of ensuring you take them. Some people like opening 10 bottles of pills every
day. Other people like to get the little zip lock bags and portion out the week's ration in daily dose baggies on Sunday, then they can just grab a
baggie and go.