Various FFQs have been tested to estimate vitamin D intakes in adults. These are two research papers that may be useful: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2865138/
We developed and validated a web-based FFQ that includes portion size images. The published paper is in JAND: http://www.andjrnl.org/article/S2212-2672(13)01776-0/abstract