Nutrition basics
Learning Center
Digestion: How long does it take?
Digestion takes about two to five days, depending on your system.
Dietary supplements for erectile dysfunction: A natural treatment for ED?
Some dietary supplements for erectile dysfunction might work and some might be dangerous. Get the facts.
Dietary fiber: Essential for a healthy diet
Some of the health benefits of eating dietary fiber might surprise you. Find out what fiber can do for you and how to get more in your diet.
Dietary fat: Know which to choose
Not all fat is created equal. Find out which type of fat to choose — and which to avoid — for good health.
Diet soda: How much is too much?
Diet soda may help you cut calories, but other low-calorie options abound.
Did the definition of Alzheimer's disease change?
What the change in the research definition of Alzheimer's disease means for you.
Diarrhea
Diarrhea: Symptom — Overview covers definition, causes of acute and chronic diarrhea.
Demyelinating disease: What can you do about it?
Learn the causes and types of these diseases that affect the protective covering of nerves, which include multiple sclerosis. Also learn how they're treated.
Delusional parasitosis
Learn more about this condition and positive steps you can take to manage the symptoms.
Delayed ejaculation
Learn what can cause delayed or absent ejaculation and how it can be treated.