A registered nurse (RN) nutritionist typically requires a bachelor's degree in nursing (BSN) and a master's degree in nutrition (MS or MN). The BSN program typically takes four years to complete, and the MS or MN program typically takes two years to complete. So, in total, it typically takes six years of college to become an RN nutritionist.
Some RNs may choose to complete a one-year dietetic internship after completing their BSN and before starting their MS or MN program. This internship can provide valuable clinical experience and help prepare RNs for a career in nutrition.