Let's forget for a moment that you just added some much needed vitamin C and thousands of phytonutrients to your body. It is little known that the the acidity of the orange itself (or any citrus fruit) has nothing to do with the residue in the body after digestion.

The body's pH is that of its tissue and fluids, after all of the digestive processes are complete. Minerals such as calcium, magnesium, potassium, and sodium that are extracted through this process help the body balance the pH levels against too much acidity or alkalinity. But that orange had an acid pH, didn't it. But did you know that you've actually taken a step in maintaining a healthy pH balance. The potassium and calcium found the orange are essential minerals that are left behind to balance the the body's pH. It has been widely accepted for some time now that.

Acid - Alkaline Diet - How to Avoid Damaging Effects Leading to Chronic Disease You might not know it...but that orange you ate with breakfast was alkalizing to your system.