Are there any vitamins that human body needs but doesn't fully produce ?

Human body needs a lot of supplements, but does it fully produce everything it needs ? Is it good to supply our body with artificially made vitamins and similar supplements ?

via Smart Health Shop Forum http://feedproxy.google.com/~r/SmartHealthShopForum/~3/ms0RUS9hW9A/9822-there-any-vitamins-human-body-needs-but-doesnt-fully-produce.html