The purpose of this study was to investigate the effect of calcium (Ca) and vitamin D (vit. D) levels on metabolism of various minerals such as Ca, P, Mg, Fe, Zn, Cu, and Cr. The comparison was made on the rats that were placed on diet containing powdered skim milk with different Ca and vit. D levels for 5 weeks. A total of 42 5-week-old Sprague- Dawley rats were divided into 7 groups as follows: Control group consisted of normal Ca and normal vit. D (0.5% Ca, 1,000 IU vit. D); Experimental groups were divided into low (0.25%) and high (1.0%) calcium levels; and vit. D group was divided into low (10 IU), normal (1,000 IU), and high (5,000 IU) subgroups. The weight gain and food efficiency ratios of the rats were not significantly different with increasing dietary Ca levels. The absorption rates of 7 minerals (Ca, P, Mg, Fe, Zn, Cu, and Cr) were significantly decreased with increasing dietary Ca levels. Also, fecal excretion of P significantly increased with increasing dietary vit. D levels (p<0.05), and urine excretion of Fe was significantly increased with increasing dietary vit. D levels (p<0.001). The result indicated that higher Ca intake affected on bioavailability of other minerals, due to interactions among minerals in the process of intestinal absorption. However, vitamin D intake had no effect on bioavailability of several minerals. Therefore, it could be suggested that adequate Ca intake is important for balance of the minerals.

The Lactobacillus brevis 340G strain isolated from traditional Korean fermented food (kimchi) produced 15.50mMof γ-aminobutyric acid (GABA) after 48 h of cultivation in MRS media containing 1% L-monosodium glutamate(MSG). The culture conditions of Lb. brevis 340G were optimized for GABA production. Lb. brevis 340G was cul-tivated at 30oC in optimized MRS media containing 3% sucrose and 2% yeast extract with 3% MSG, resulting inmaximum GABA production (68.77mM) after 54 h of cultivation. Skim milk fermented with Lb. brevis 340G pro-duced 4.64mM of GABA in the presence of 1% MSG. These results suggest that Lb. brevis 340G could be usedas a starter for functional fermented foods and skim milk fermented with Lb. brevis 340G could be further devel-oped to become functional dairy food fortified with GABA.