Optilets-M-500

Are these vitamins still manufactored? If so where may I purchase them? I have taken them for at least 20 years and am now told by the pharmacies that they are no longer available. They have proven to be the only vitamin that helps me in regards to stamina and strength and just an overall good healty feeling.

I appreciate your response and if there is another vitamin that is equal to Optilets-M-500, please let me know.

Margie Gaudin