Do Grapefruits Contain Vitamin C?
Grapefruits DO contain vitamin C.
More Info: If you are seeking to increase your vitamin C intake through dietary measures, grapefruit tops the list. One serving, one-half a grapefruit, contains 39 mg of vitamin C, which is 65% of the daily value. 
Little did Count Odette Phillipe realize that the seeds of the forbidden fruit that he brought to the American shores from the Bahamas in 1823 were jammed packed with nutrition. In fact, the seeds that were quickly dispersed throughout Safety Harbor Florida were grown strictly for their aesthetic value. Today, the strange exotic fruit that grows in clusters like grapes is recognized as a healthful addition to any diet. 
How Much Vitamin C in Grapefruit?
The serving size for grapefruit is one-half of a medium grapefruit. The average serving of grapefruit contains an average of 39 mg of vitamin C. This is 65% of your daily value. A full grapefruit will provide you with 130% of your daily value of vitamin C.
If you want a quick dose of vitamin C without the work, consider a shot of grapefruit juice. Three-quarters of cup contains 70 mg of vitamin C, or 117% of your daily value. Keep in mind when juicing fruits that the sugar content is higher and you are missing out on the wholesome benefits of the fiber in the fruit flesh. 
What Does Daily Value (DV) Mean?
The daily value is the US Food and Drug Administration's (FDA) version of the Institute of Medicine's recommended daily allowances for vitamins and minerals. The daily value was established for labeling purposes to help consumers measure the nutritional value of a food product in relation to their total diet. This number should not be confused with the RDA, which is measured by age and gender. (For example, the RDA for vitamin C is 75 mg for women and 90 mg for men over the age of 19). The daily value (DV) for vitamin C is 60 mg for adults and children aged 4 and older. 
Grapefruit Tops the List
In terms of vitamin C content, grapefruit is not far from the top of the list, surpassed only by a few vitamin C rich foods. A serving of grapefruit juice comes in third after sweet red pepper, containing 95 mg of Vitamin C per half cup, and orange juice, containing 93 mg per three-quarters cup. The fruit contains slightly fewer milligrams and is surpassed by kiwifruit, green bell pepper, broccoli, strawberries, and Brussels sprouts in order of vitamin C content. 
Pink/Red More Nutritious than White
If you like both white and red grapefruit equally, opt for the red. Both white and red have essentially the same amount of vitamin C, but the red contains significantly more vitamin A, lycopene, and beta-carotene. 
Grapefruit not Healthy for All People
Unfortunately, not everyone is able to enjoy the health benefits of grapefruit. In fact, grapefruit can be potentially fatal to those taking certain medications. The body requires an enzyme to break down particular medications in the body. The furanocoumarins contained in grapefruit block this enzyme, which inhibits their metabolism, causing these medications to build up to toxic levels in the body. There are currently more than 85 drugs that interact with grapefruit and the number is rising as new studies and new drugs emerge. 
In general, the types of drugs that are affected by furanocoumarins are drugs to treat high blood pressure, statins, immunosuppressants, protease inhibitors, and some antihistamines and anti-anxiety medications. You need to read and adhere to the warning labels that accompany any medication.