This paper presents a method for quantitative analysis of urine vapor and breath using gas-liquid partition chromatography. The technique allows for the determination of about 250 substances in a breath sample and about 280 substances in a urine vapor sample. The method is based on a standardized diet that eliminates intestinal flora and ensures consistent body fluid composition, enabling accurate quantitative analysis. The technique is useful in orthomolecular medicine, which focuses on maintaining health and treating disease by adjusting the concentrations of substances naturally present in the body. The study highlights the importance of individual variation in the optimal intake of essential substances, such as ascorbic acid, and suggests that higher intakes may be beneficial for some individuals. The research also emphasizes the value of thorough quantitative analysis of body fluids for differential diagnosis of diseases. The authors developed instrumental techniques to analyze the molecular composition of body fluids, including urine, blood, spinal fluid, breath, saliva, and tissue. The use of a completely defined diet (Vivonex-100) ensures standardization of results. The development of computer technology has enabled efficient handling of large amounts of quantitative data. The method involves gas-liquid chromatography without preliminary fractionation, making it the fastest and most economical way to obtain extensive information about the molecular composition of individuals. The study includes chromatograms of urine vapor and breath, showing the separation and quantitation of 280 and 250 substances, respectively. The results demonstrate that the standard deviation for individual peaks on successive days is about 10% for individuals on a standardized diet. The research was supported by a grant from the National Institute of Mental Health and involved collaboration with Vivonex, Inc.This paper presents a method for quantitative analysis of urine vapor and breath using gas-liquid partition chromatography. The technique allows for the determination of about 250 substances in a breath sample and about 280 substances in a urine vapor sample. The method is based on a standardized diet that eliminates intestinal flora and ensures consistent body fluid composition, enabling accurate quantitative analysis. The technique is useful in orthomolecular medicine, which focuses on maintaining health and treating disease by adjusting the concentrations of substances naturally present in the body. The study highlights the importance of individual variation in the optimal intake of essential substances, such as ascorbic acid, and suggests that higher intakes may be beneficial for some individuals. The research also emphasizes the value of thorough quantitative analysis of body fluids for differential diagnosis of diseases. The authors developed instrumental techniques to analyze the molecular composition of body fluids, including urine, blood, spinal fluid, breath, saliva, and tissue. The use of a completely defined diet (Vivonex-100) ensures standardization of results. The development of computer technology has enabled efficient handling of large amounts of quantitative data. The method involves gas-liquid chromatography without preliminary fractionation, making it the fastest and most economical way to obtain extensive information about the molecular composition of individuals. The study includes chromatograms of urine vapor and breath, showing the separation and quantitation of 280 and 250 substances, respectively. The results demonstrate that the standard deviation for individual peaks on successive days is about 10% for individuals on a standardized diet. The research was supported by a grant from the National Institute of Mental Health and involved collaboration with Vivonex, Inc.