Nutritional supplements are good for those who sell them.

http://www.medscape.com/viewarticle/871848?src=WNL_infoc_161203_MSCPEDIT&uac=7267HX&impID=1244516&faf=1#vp_1

Supplements may also backfire...
http://www.medscape.com/viewarticle/829860?src=WNL_infoc_161203_MSCPEDIT&uac=7267HX&impID=1244516&faf=1

And Med Diet is good:
http://www.medscape.com/viewarticle/870519?src=WNL_infoc_161203_MSCPEDIT&uac=7267HX&impID=1244516&faf=1

Perhaps a few exceptions:
- Long chain W3 supplements if you don't eat fish and seafoods
- Protein from whey if you exercise a lot
And that's all...