For the past few years I have asked for a copy of the lab results, and my doctor has very willingly had a copy made for me. You can then see exactly what’s tested for, where in the “normal” (reference) range you fit on each one, etc. It can occasionally be enlightening. Be aware that if you ask for the 25(OH)D test for Vitamin D, the low end of the “normal” range at most labs still shows what is now considered a deficiency. As per the link in the earlier post (to the Vitamin D Council web site), somewhere in the 80-90 range is quite good.
It takes less sunlight than most people realize to get adequate vitamin D produced in your body, though with just a facial exposure and the low angle of the sun in the winter, you aren’t going to produce much if any. The above-linked article also has a good discussion about exposure and exposure times for adequate vitamin D. I wonder if I’m possibly above the normal range in the summer, actually, since it occurred to me that I’m at the high end of the normal range when I get my physical (generally in the middle of the winter). Even down south, I don’t get all that much sun exposure in the winter (more covering, also low sun angle compared to summer), yet I’m still in the high end of the range just with supplementation. You’re probably doing just fine in the summer, but a test is pretty definitive (I haven’t bothered with multiple tests per year as discussed in the article, though).
As for multivitamins, choose very carefully. Most are somewhere between a waste of money and harmful. Check the vitamin A source – if it’s retanol, I won’t take it (nothing but beta-carotene in ours). There’s some evidence that the retanol form of vitamin A actually cuts vitamin D usage in the body (see this article at Vitamin D Council if interested). And the vitamin D type/source should be specified (as should ALL sources) if the supplement is even worth buying. The other one that gives a good clue as to the quality of the supplement is vitamin E. If the type starts with the letters “dl” as opposed to just “d,” dump it – it synthetic. The other clue is the spelling of the substance name – natural is spelled “tocopherol” while synthetic is “tocopheryl.” The cheapest vitamins (as in “cheap” with a strong sarcastic sound) have dl-alpha-tocopheryl, not d-alpha-tocopherol (the natural form).