Kendra Wilkinson suffers from seasonal affective disorder (SAD).

Kendra Wilkinson

Kendra Wilkinson

The 31-year-old reality TV star has admitted she is currently coping with SAD, which is a specific type of depression that comes and goes according to the seasons of the year.

She shared on Twitter: "I don't know about u guys but I feel crazy around the holidays. Moody n s**t. Maybe im like this year round n don't know tho.

"Lack of vitamin D they say ... been gettin that extra D ... maybe I should actually take the vitamin tho. (sic)"

The symptoms of SAD tend to be more severe during the winter months and can return in a repetitive pattern.

The condition can cause sufferers to feel low, lose interest in normal everyday activities and feel lethargic.

But Kendra revealed she was considering taking vitamin D supplements as a means of making up for the lack of sun during the winter months.

She said: "Somehow they trap the sun rays in a pill n take it to supplement. I'll never understand. (sic)"

In August, meanwhile, Kendra admitted to suffering from "empty nest syndrome" after her two-year-old daughter Alijah started school.

The blonde beauty - who also has six-year-old son Hank with her husband Hank Baskett - previously insisted she had no ambitions to have a third child, but revealed she began to feel lonely and broody after her daughter started school.

Asked about the possibility of having more children, she said: "I said, 'absolutely not,' but now our daughter just entered pre-school and that second that she went into the pre-school, I got empty nest syndrome already."

Kendra - who previously was a live-in girlfriend of Playboy founder Hugh Hefner - and her husband were involved in a much-discussed cheating scandal in 2014, but they have since worked out their differences with the help of therapy.

But Hank - who was alleged to have cheated on his wife with transgender YouTube model Ava Sabrina - was always convinced he was the right man for Kendra.

He previously told Kendra: "'No one will understand you and treat you like I do.'

"I was like, 'You can go on out - me and the kids will still be here - so you can make your decision. I'll be here comfortable, but go play around if you want.'"