australia National Center for Biotechnology Information NCBI NLM MEDLINE humans pubmed abstract nih national institutes of health national library of medicine research support non-u.s. gov't adult female male middle aged time factors seasons skin / chemistry ultraviolet rays robyn m lucas radiometry affs=[] is_editor=false suffix=none equal_contrib=false) initials='a' initials='b' initials='p' initials='k' initials='d' skin pigmentation / physiology sunlight* affs=[]) initials='c' author(firstnames='david' initials='i' lastname='williams' initials='r' initials='t' author(firstnames='trevor' author(firstnames='patricia' initials='mp' equal_contrib=false)] author(firstnames='keith' lastname='taylor' pmid:23311500 doi:10.1111/php.12044 patricia valery collabauthor(name='ausimmune investigator group' investigators=[author(firstnames='caron' lastname='chapman' author(firstnames='alan' lastname='coulthard' lastname='dear' author(firstnames='terry' lastname='dwyer' lastname='kilpatrick' author(firstnames='robyn' lastname='lucas' author(firstnames='tony' lastname='mcmichael' author(firstnames='michael p' lastname='pender' author(firstnames='anne-louise' lastname='ponsonby' initials='al' author(firstnames='bruce' lastname='valery' author(firstnames='ingrid' lastname='van der mei' environmental exposure / statistics & numerical data* radiation dosage* vitamin d / blood* vitamin d deficiency / blood*