Zinc (Zn) deficiency is one of the most common nutritional deficiencies worldwide. It is associated with reduced nutritional status and has been reported in cases of growth retardation, alopecia, and decreased serum alkaline phosphatase (ALP). It has also been reported to occur during total parenteral nutrition (TPN) administration and is associated with various diseases, such as liver diseases, diabetes, and kidney disease. We used Zn-deficient mice of ICR and C57BL/6J strains to investigate the various effects of Zn deficiency on the body, assuming that a healthy person may also become deficient in Zn either due to an unbalanced diet or malabsorption. The results showed that a Zn-deficient diet suppressed body weight gain and increased the tissue weight of the kidneys and cecum in both strains of mice. Biochemical data showed no decrease in serum ALP activity in either strain. Furthermore, in C57BL/6J mice, a Zn-deficient diet caused alopecia, loss of villi in the small intestine, and eventually affected the intestinal mucosa, which could be a risk factor for poor nutritional status. Although previous reports have shown that serum ALP activity is decreased during Zn deficiency, this is the first study that used 4-wk-old mice of ICR and C57BL/6J strains to show that serum ALP activity, which is a Zn deficiency marker, did not decrease in the two strains of Zn-deficient mice; furthermore, a Zn-deficient diet causes various symptoms.