The normalized results for vitamin B12 stability
are shown in figure 1 (absolute concentrations
varied from 193 to 1343 pg/mL). Vitamin
B12 concentrations under all four storage
conditions followed similar patterns of an initial
rise followed by a fall after 1 to 3 days. The
frozen specimens showed an initial peak at 1
day of storage, followed by a decrease which
dropped below the zero hour concentration at 7
days. The refrigerated specimens also showed
a rise in vitamin B12 concentration which was
initially fast, and at 3 days reached a level of 18
to 28 percent higher than the initial concentration.
After day 3, the relative vitamin B12
concentration decreased by about 25 percent