The purpose of this diet is to keep the levels of electrolytes, minerals, and fluid in your body balanced when you have chronic kidney disease or are on dialysis. People on dialysis need this special diet to limit the buildup of waste products in the body.
Vega is the brightest star in Lyra, and the fifth brightest star in the sky. It is the third brightest star in the Northern night sky, after Sirius and Arcturus, and can often be seen near the zenith in the mid-northern latitudes during the Northern Hemisphere summer.
Most stars you can see with your naked eye are considerably redder than Vega, and thus have positive (B-V) values. Another way to look at the color index is to go back to the convolution of spectrum with passband. Convolving the spectrum of a hot star with the B and V passbands ... yields a lot more energy (and photons) in the B-band than the V-band.