For my husband:

Beriberi is caused by a lack of thiamine (vitamin B1). Its symptoms include weight loss, emotional disturbances, impaired sensory perception, weakness and pain in the limbs, and periods of irregular heart rate.

Scurvy is a disease resulting from insufficient intake of vitamin C, which is required for correct collagen synthesis in humans. Scurvy leads to the formation of spots on the skin, spongy gums, and bleeding from all mucous membranes.

Rickets' is a vitamin deficiency disease of infancy and early childhood caused by lack of vitamin D. Rickets causes soft bones because enough vitamin D is not present to assist in calcium absorption. When enough calcium is not absorbed by the bone, it does not harden properly, and is too soft to support the weight of the growing body properly.

And yes, "Severely bowed legs can be a sign of rickets."

What brought this about? This simple statement by me today: Berry berry kix when left in a bowl all day require a crowbar to pry off the side of the bowl.
Although to be fair every time I bring up a taking a vitamin he brings up scurvy and asks what disease it is that makes you bowlegged.

Then this conversation went where they usually do. Into an argument about which one of us is smarter and funnier. To which he always throws out his immense knowledge of self-described useless music and lyrics trivia.