I am an 19 year old female. when my toes get just slightly cold they turn white, numb, and sometimes lose feeling. its only in my right foot.

Raynauds.: It sounds like the perfect description of Raynaud's phenomena. It is a spasm of the small blood vessels in the toes, in your case, when exposed to cold. There are multiple reasons thought to be the cause and treatment is based on avoiding conditions and environs that can trigger the response. To remove all doubt, consult with your primary care provider for the latest treatment.

Raynauds : You are describing raynauds which is opening and closing of the capillaries and small blood vessels in the hands and feet made worse by colder temperatures, stress, certain medications, or smoking for example. Since it is occurring in one foot you need an ultrasound of that foot and leg., a fill history and physical exam and lab tests. Raynauds can be associated with autoimmune illnesses

Need examination: To rule out vascular insufficiency. Symptoms are similar to those that occur with Raynaud's phenomenon