Underwatering can cause leaves to shrivel and die. Jades prefer to be kept on the dry side, but not bone dry like a cactus. When you water, always be sure to water thoroughly so that the entire rootball is saturated.

Nutrient deficiency usually occurs when the soil pH is outside the preferred range, not because the plant needs fertilizer. However, the symptoms you describe can also result from mineral overload if your local tap water is on the hard side. If that is the case, flush lots of filtered, distilled or rainwater through the rootball to wash away the excess mineral salts.