Sixteen experiments with men subjects on basal diet and on the same basal supplemented by fresh grapes, fresh natural grape juice, detartrated grape juice, natural grape juice concentrate, concentrate-tartrate mixture, Thompson seedless and Muscat seeded raisins are reported. The following results were observed when the grapes or grape products were added to the basal ration. These results are applicable to grapes and grape products of the varieties and types investigated. The writer wishes to express his appreciation of the interest and thoughtful consideration of Professor W. V. Cruess, upon whose suggestion this study was initiated. The friendly advice of P. F. Nichols of this laboratory has been of great assistance. The full cooperation of the men taking a part in the diets is acknowledged with pleasure.