Gene-diet interactions can have major effects on human development, aging and response to medical therapy. In particular, this is true for key nutrients such as Vitamin A, D, B9 and B12. Unfortunately, the current “one size fits all” approaches for determining whether an individual has adequate levels of these and other micronutrients relies on older studies that use serum assays that only capture recent intake that do not capture the health care challenges incurred by our now aging, more diverse population We believe that integrated genetic-epigenetic assessments of saliva DNA can better capture cellular micronutrient status and serve as a cornerstone of future Precision NutriEpigenomic therapies. Our method, which does not require drawing blood, will be robust against day-to-day dietary intake fluctuations and can be conducted using remote, telemedicine type approaches. This more functionally oriented method could find widespread use in a variety of both medical and non-medical nutraceutical settings in optimizing athletic performance, facilitating healthy aging and monitoring nutritional supplemental of both chronic (e.g., digestive disease) and acute (e.g., chemotherapy) patients. For example, the method is generalized for the assessments targeting the use of common supplements such as Nicotinamide Adenine Dinucleotide (NAD+). We hypothesize that integrated genetic-epigenetic signatures of saliva DNA will robustly predict serum B9 and B12 levels. To test that hypothesis, we will use data from a cohort of 450 African Americans for whom we already have serum, genome wide genetic, and genome wide epigenetic data from whole blood DNA. We will use machine learning to first mine the most predictive biosignature for serum B9 and B12 levels. Next, using our patent-pending, proprietary techniques, we will translate that whole blood (WB) DNA based signature into a saliva-based signature. Then, we will transform the test into an easy to perform set of methylation sensitive digital PCR assays. If successful, the project will have high impact because it could lead to painless, at-home nutraceutical testing. It is significant because certain nutrients are thought to be protective against cancer or premature aging. Our plan is highly feasible because the large body of prior work, abundant biomaterials, and our expertise in both epigenetics and machine learning. It is innovative because saliva diagnostics have not yet been introduced to the nutraceutical market. The BD team is well qualified. The project will led by Dr. Rob Philibert, an expert in epigenetic diagnostics. He will be assisted by a team of co-investigators that includes experts in nutrition (Dr. Ruth Grossman) and biostatistics (Dr. Jeff Long). If successful, this R43 will serve as the basis for an R44 that develop a battery of saliva based nutritional assays.