Airborne (dietary supplement)
Airborne is a dietary supplement and health formula which is claimed to help ward off harmful bacteria and germs, and help prevent the flu and the common cold.  The formula contains herbal extracts, amino acids, antioxidants, electrolytes, vitamins, and other nutrients, and can be purchased in many U.S. retail stores over-the-counter in three different forms:  a tablet which can be taken orally or dissolved in water, a chewable "Gummi" lozenge, or a concentrate powder.

# Invention and retail success
The formula for Airborne was developed by Victoria Knight-McDowell, an elementary school teacher from Carmel, California.  In the early 1990s, she began brewing herbal and vitamin cocktails (in hopes of warding off the germs spread by her second-grade students), "experimenting with vitamins C, E, and A, as well as zinc, selenium, and herbs including forsythia, ginger, isatis root, and echinacea."  When she felt she had developed an effective preventive formula against colds, Knight-McDowell began selling it in tablet form to local drug stores.  Over the next few years, largely by word-of-mouth, the formula's popularity grew. In 1997 specialty grocery chain Trader Joe's ordered 300 cases of Airborne tablets to sell, and by 1999 other larger chains, such as Wal-Mart and Rite Aid, began stocking Airborne. It has been ranked the #1 cold and flu remedy at Drugstore.com and is considered one of the fastest selling health products in retail history.

# Testing, research, and controversy
Although it is recommended that Airborne be taken "at the first sign of a cold symptom, or before entering crowded environments, like airplanes and offices," the package explicitly states that Airborne is "not intended to diagnose, treat, cure, or prevent any disease."  This is because Airborne has not undergone any testing by the US Food and Drug Administration (FDA), and Knight-McDowell Labs would be violating FDA regulations on Structure/Function claims were they to state on the packaging that it cured or prevented any disease.

## Effectiveness studies
Scientific studies supporting Airborne's effectiveness are few in number. The study often referenced in favor of Airborne was sponsored by the Knight-McDowell Labs, manufacturers of Airborne. "GNG Pharmaceutical Services Inc.", claims to have conducted this study with 120 people, and reported that 47% of Airborne recipients showed little or no cold or flu symptoms, whereas only 23% of the recipients of a placebo pill showed equal results.  However, in February of 2006, ABC News discovered that GNG Pharmaceutical Services has no official clinic, scientists, or even doctors.  In fact the company comprises only two men, who started the company just to perform this study.  Because of the bad publicity that this controversy has brought forth, Knight-McDowell Labs has removed all references to the study from their packaging and web site.
For full article on Vitamin C and the debate over its appropriate dosages, see Vitamin C.
A medical report on drugs and therapeutics regarding Airborne, along with its emphasis that the evidence of cold prevention or treatment of the formula is inconclusive, gives reason to believe that the supplement is unsafe as directed, specifically regarding its excess of vitamin C:
There are some concerns.  First, there is no conclusive evidence that this product or any of its ingredients prevents colds or shortens their duration. Second, the adult tablet contains 1 g of vitamin C, and the directions for use advise taking 1 tablet at the first sign of a cold and repeating the dose every 3 hours as necessary.  Vitamin C in doses higher than 1 g increases oxalate and urate excretion and may cause kidney stones (EN Taylor et al, J Am Soc Nephrol 2004; 15:3225). Third, the safety of this herbal extraction combination has not been established. And with herbs and dietary supplements in general, we only have the manufacturers word on the label for whats in them.
It has been determined that extreme amounts of vitamin C can lead to death, although in recent publications, the link between excess doses of vitamin C and kidney stones has been disputed along with severe constipation and blood in stool.  However, Airborne's 5,000 IUs of vitamin A per serving has become another major health concern. The recommended safe upper limit for vitamin A is 10,000 IUs daily.  This amount is easily exceeded when following Airborne's directions, as it is stated on the packaging, to "repeat every three hours as necessary" (with a maximum of three doses per day).
Pregnant women especially are advised to exercise extreme caution regarding Airborne consumption. Excess preformed vitamin A (from as little as only twice the daily recommended amount) during early pregnancy has been associated with a significant increase in life-threatening birth defects.  Vitamin A is indeed necessary for fetal development, but most women already carry stores of it in their fat cells.  Researchers recommend that pregnant women either restrict their supplemental consumption of vitamin A to 4,000 - 8,000 IUs daily, or they should instead consume beta carotene.

# Supplement facts and ingredients
Following are the supplement facts of the original Airborne tablet.  Though the ingredients of other versions of Airborne vary slightly to produce different flavors and functions, all of what would be considered the active ingredients of the formula are included below.
- Calories: 5
- Sodium: 230mg
- Total Carbohydrates 0g
- Sugars 0g
- Protein 0g
- Vitamin A (Palmitate) 5,000 IUs
- Vitamin C 1,000mg
- Vitamin E (Acetate) 30 IUs
- Riboflavin 2.8mg
- Magnesium (Oxide & Sulfate) 40mg
- Zinc (Sulfate) 8mg
- Selenium (Amino Acid Chelate) 15mcg
- Manganese (Gluconate) 3mg
- Potassium 75mg
- Amino Acids (Glutamine as L-Glutamine, Lysine as L-Lysine HCl) 50mg
- Proprietary Blend 350mg: Maltodextrin, Lonicera, Forsythia, Schizonepeta, Ginger, Chinese Vitex, Isatis Root, Echinacea