Vitamins supplements over the counter are not regulated by any one or any credible labs--so much has been written by the lack of oversight in the last few years! Only prescribed supplements should be used, the over the counter's supplements are too often not what they claim to be.

Save your wallet and your health. Where you live should not make much of a difference since a lot of europeans live well North of the 45th parallel with no ill effects! (Minneapolis is almost at that latitude)
For most of us a good well balanced nutrition is by far healthier!