I had too much Sugar the day/week/month before.
I had too much alcohol the day/week/month before.
I had too much fruit or too much salad the day/week/month before.
I know that in a normal healthy person upsetting the balances is very easy - and certainly in my case never had a thing to do with Iodine or bromide.
Hairloss is lack of Yin some say... that would be a salts imbalance for sure.
But, that is only one possible cause.
People who eat too many carrots or take too much Vitamin A lose their hair, too.