Common diseases
That fluff comes with a downside

My experience: I had a routine before I got my chickens with my ducks already using supplement vitamins, but I stepped it up about abit when I learned about silkies need for more vitamins.

I use a powder Vitamin on their feed which I sprinkle on at each serving. My feeling is that its easier to control how much vitamins they get from their feed rather using it in their water.

BUT I also give them liquid vitamins in their water once a week, just to make sure they get what they need. I copied this routine from my chicken mentor.

Since I also have a girl that have had wry neck twice, despite the extra vitamins.

My experience: I have a hen with mild vaulted skull. I bought her with purpose knowing she had this. i asked for a hen that was not breeding standard. While many breeders cull a chick directly with vaulted skulls. This breeder gives them a chance since they still can live long lives. She is 1,5 Year old at this point. Everytime she trips of high heights, get pecked on or even get mated. I do get a twist in my stomach, that she is going to get a brain inury. I'm very careful doing anything to her head, such a thing just putting a bowtie on her (yes I do that my chooks), instead I put it on her chest instead or just brushing her crest.

Unfortantly silkies are prone to certain conditions and diseases. 

Quote from avian vet: "...of all the chickens that come to me with issues, silkies are a majority that come thrue those doors..."

First they are very prone to vitamin deficincies, with the most common being vitamin E, which causes Wry neck. A disease which casues them to loose the control of the muscles in their neck.

With this in mind, you need to be extra meticulous how much vitamins your silkies get. Most feed stores have vitamin supplements for chickens, you can spread on their food or liquid form you can have in their water.

Second is that they can be born with a sort of brain hernia, called Vaulted skull. Unfortantly this is very common that silkies are born with and it can vary how serious the hernia is.
Basicly its a hole in their skull where only skin protects the brain. A chick born with mild to medium vaulted can have a real quality of life but they will be more sensetive to a bump on the nogging and they can devolp neurological problems.

With the right breeding the amount of vaulted skulls born can be reduced.