A normal range for blood urea nitrogen is generally 8 to 24 mg/dL for adult men (2.86 to 8.57 mmol/L) and 6 to 21 mg/dL (2.14 to 7.50 mmol/L) for adult women. However, urea nitrogen levels vary by age. Infants have lower levels than other people do.
Fortunately, freezing zucchini and other summer squash is a snap: All you do is cut it into half-inch slices, blanch it in a pot of boiling water for three minutes, transfer it to a bowl of ice water to cool, drain it, and bag it.
You can keep zucchini squash almost indefinitely if you pickle and jar it. Combine one pound of sliced zucchini with one cup of sliced onions and two tablespoons of salt in a non-reactive pot. Add enough water to cover the vegetables, and let the pot stand for two hours.