Re: How would you test the vitamin content of milk in a light block bottle?

From: http:
//www.ext.vt.edu/news/periodicals/foods/products/99feb-09.html
"Milk/Vitamin D: Opaque containers protect milk by blocking light which 
breaks down vitamin A and riboflavin. Fluorescent light can destroy 70 
percent of vitamin A and 20 percent of riboflavin. Sunlight depletes 
vitamins more quickly, but white light from household bulbs destroys 
nutrients more slowly. As milk loses it nutrients, flavor losses become 
quite pronounced. (Tufts Univ. Health & Nutrition Letter Jan 1999)." 

The biggest hurdle for your science fair project would be the vitamin 
analysis.  Vitamin anaylsis would take considerable scientific expertise 
and equipment.  For instance, I checked the web for similar projects and 
found none.  

Using Alta Vista http://www.altavista.com
and the search terms: +"science fair" +milk +nutrient +light
23 pages turned up.  Other search engines would yield similar results
One page was:  
http://members.aol.com/ScienzFair/microbio.htm

Here's a 1996 project that was similar but I suspect analytical problems 
stymied the project as I see no data. 
http://hine.k12.dc.us/~scifair/1996/biochem/tomia.html

You might try your State Extension Service people in Amherst, MA for 
information and ideas. 
http://www.reeusda.gov/statepartners/ma.htm
Here's a list of people: 
http://www.umass.edu/umext/programs/4h/people_educators.htm

I'd ask for a dairy scientist as they'd know the literature of light 
effects on milk and perhaps would have a suggestion for a suitable science 
fair project.  For example, the effect of light on taste would fairly simple to 
preform.  Add a literature search on how various light frequencies 
stimulate certain chemical reactions in milk and your daughter would have 
a "tasty" project. Remember, the judges also grade on how well the 
scientist understands the science behind the project. Lotsa chemistry and 
physics here.

Good luck