Capsaicin (red-chilli pepper) should be "hot" enough
as a supplement, don't you think?
If you live in a temperate climate and it's winter,
sunshine is a rarity...well, go for cod liver oil:
a relic from the past for some,
number-one-super-food for others!
By the way, there is a CLO topic
right HERE
ikod
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.kochpiraten.de%2Fimages%2Farticles%2Fcapsaicin.jpg&hash=3265cd87cf875fcc8170f578e8e3b6de) (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fanatomy.yonsei.ac.kr%2FLWT%2Fimages%2FCapsaicin.jpg&hash=abba35e61c7629b6a5accd40b2191d10)
http://www.kochpiraten.de/images/articles/capsaicin.jpg
http://anatomy.yonsei.ac.kr/LWT/images/Capsaicin.jpg