Objective:~This study aims to investigate if the proportion of NET patients with normal vitamin values can be increased, with vitamin suppletion and a personalized diet.~Methods:~This is a single center 18-week open-label, non-comparative, single-arm, intervention study. After inclusion and the first measurements, adult patients with metastasized or irresectable NET will continue with four weeks of standard treatment. After these four weeks participants with vitamin values below normal will get vitamin suppletion for each deficient vitamin and all participants will get the dietary intervention during 14 weeks. Effects of the intervention will be evaluated by quantitative analysis of blood and urine and questionnaires. The measurements, including; baseline characteristics, quantitative analysis of blood and urine and questionnaires will be performed at baseline (t=0), after 4 weeks (t=4) and after 18 weeks at end of study (t=18). Furthermore at t=18 a semi-qualitative interview will be performed.
This study aims to investigate if the proportion of neuroendocrine tumor (NET) patients with normal vitamin values can be increased, with vitamin suppletion and a personalized diet, Effects of the intervention will be evaluated by quantitative analysis of blood and urine and questionnaires. The measurements, will be performed at baseline (t=0), after 4 weeks (t=4) and after 18 weeks at end of study (t=18). Furthermore at t=18 a semi-qualitative interview will be performed.