Vitamin D and its major metabolites: serum levels after graded oral dosing in healthy men.
Barger-Lux MJ, Heaney RP, Dowell S, Chen TC, Holick MF.
Osteoporos Int. 1998;8(3):222-30.
PMID: 9797906
Barger-Lux MJ, Heaney RP. Effects of above average summer sun exposure on serum 25-hydroxyvitamin D and calcium absorption.J Clin Endocrinol Metab. 2002 Nov;87(11):4952-6.PMID: 12414856 [PubMed - indexed for MEDLINE]
Barger-Lux MJ, Heaney RP, Dowell S, Chen TC, Holick MF. Vitamin D and its major metabolites: serum levels after graded oral dosing in healthy men.Osteoporos Int. 1998;8(3):222-30.PMID: 9797906 [PubMed - indexed for MEDLINE]
Conclusions: Healthy men seem to use 3000-5000 IU cholecalciferol/d, apparently meeting > 80% of their winter cholecalciferol need with cutaneously synthesized accumulations from solar sources during the preceding summer months. Current recommended vitamin D inputs are inadequate to maintain serum 25-hydroxycholecalciferol concentration in the absence of substantial cutaneous production of vitamin D.
Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol.
Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ.
Am J Clin Nutr. 2003 Jan;77(1):204-10. Erratum in: Am J Clin Nutr. 2003 Nov;78(5):1047.
PMID: 12499343