IMO...I would think they are okay. A good place to start might be asking your doctor or if you have an honest sales person in a nutrition place, they might be able to tell you. Here is some information that might help...

Drugs Frequently Potent Past Expiration


By Laurie P. Cohen

Do drugs really stop working after the date stamped on the bottle? Fifteen years ago, the U.S. military decided to find out. Sitting on a $1 billion stockpile of drugs and facing the daunting process of destroying and replacing its supply every two to three years, the military began a testing program to see if it could extend the life of its inventory.

The testing, conducted by the U.S. Food and Drug Administration, ultimately covered more than 100 drugs, prescription and over-the-counter. The results, never before reported, show that about 90% of them were safe and effective far past their original expiration date, at least one for 15 years past it.

In light of these results, a former director of the testing program, Francis Flaherty, says he has concluded that expiration dates put on by manufacturers typically have no bearing on whether a drug is usable for longer. Mr. Flaherty notes that a drug maker is required to prove only that a drug is still good on whatever expiration date the company chooses to set. The expiration date doesn't mean, or even suggest, that the drug will stop being effective after that, nor that it will become harmful.


MARKETING ISSUE

"Manufacturers put expiration dates on for marketing, rather than scientific, reasons," says Mr. Flaherty, a pharmacist at the FDA until his retirement last year. "It's not profitable for them to have products on a shelf for 10 years. They want turnover."

The FDA cautions that there isn't enough evidence from the program, which is weighted toward drugs needed during combat and which tests only individual manufacturing batches, to conclude that most drugs in people's medicine cabinets are potent beyond the expiration date. Still, Joel Davis, a former FDA expiration-date compliance chief, says that with a handful of exceptions - notably nitroglycerin, insulin and some liquid antibiotics - most drugs are probably as durable as those the agency has tested for the military. "Most drugs degrade very slowly," he says. "In all likelihood, you can take a product you have at home and keep it for many years, especially if it's in the refrigerator."

For what its worth, I don't see why it wouldn't apply to vit. and supplements.
Hope it helps.