Purple tint to my fingernails. Please Help.?

Hi, i just noticed sitting here in my living room that the end of my nail, (closest to my knuckles) has a slight, slight purple tint to it. Im a 16 year old male. I am 5/10 and weigh 116. I`ve heard that this can be due to a circulatory or respitory disease. Should I be urrgently worried? Or can I just go on with a healthier diet. Is there certain foods that I can eat to restore any defficiencys?