I've seen some cases of it, where it is due to lack of fresh food and vitamins.
Can vitamin suplements really make a difference here and prevent it, even if you only eat canned/long lasting foods.
I am not kidding, i've seen some minor cases of scurvy (spongy and bleeding gums), it might appear like its the year 1500, but its not. Although they rapidly got better after having a healthier alimentation.
Could have been gingevitis? For scurvy, any vitamins with vitamin C should do.Pine needle tea has a lot of vitamin C, but I have to admit I've never tried it.