Chronic inflammation has been linked to the progression of type 1 diabetes (T1D). Supplementation with vitamin D and omega-3 fatty acids, which have anti-inflammatory properties, may slow or stop the progression of T1D. A field study is underway to assess the relationship between these nutrients and T1D progression among auto-antibody positive individuals who have not been diagnosed with T1D. The T1D Prevention Field Study is currently recruiting participants to complete online health surveys and home blood-spot tests for 25-hydroxyvitamin D [25(OH)D], Omega-3 Index, AA:EPA Ratio, high-sensitivity C-reactive protein, and HbA1c every three to four months for 5 years. Participants (or their parents/guardians) are given information about the importance of achieving a 25(OH)D level between 40-60 ng/ml and an AA:EPA Ratio between 1.5-3.0 to reduce inflammation. However, participants are free to choose their own supplement or dietary regimens. Data analysis will focus on associations between vitamin D and omega-3 status and progression of T1D. Initial enrollment in the T1D Prevention Field Study includes 103 participants from fifteen countries; total enrollment is expected to reach at least 400 participants by the end of 2022. The field study approach allows for cost-effective research that capitalizes on new technologies for recruitment, data collection, and blood level testing from home. However, some challenges have arisen. Many individuals are reading the open source protocols and some choose to supplement and test on their own so incentives may be needed to increase enrollment. Additionally, some participants do not have access to auto-antibody testing or are unable to get access to their test results; therefore, there is a need to provide blood spot auto-antibody testing through the field study.