Determinants of vitamin D levels in nursing home residents.
OBJECTIVE
To determine the effect of various doses of vitamin D(2) and D(3), as well as ambulatory status (a surrogate for sun exposure), on 25-OH-D levels.


METHODS
Cross-sectional study with multiple regression analysis.


METHODS
A state veterans home for veterans and their spouses.


METHODS
Three hundred two of 609 eligible residents.


METHODS
Serum 25-OH-D and parathyroid hormone (PTH) level, supplemental dose of vitamins D(2) and D(3) per kilogram of body weight, and 3 levels of ambulatory status.


RESULTS
The mean 25-OH-D level was 28.6 + 9.2 ng/mL; 6.6% of subjects had values of 16 ng/mL or below. Thirty-two percent of participants had 25-OH-D levels below 30 ng/mL and PTH elevation based on stage of kidney disease, evidence that the suboptimal 25-OH-D level had physiologic consequences. Residents unable to transfer independently had 25-OH-D levels 1.6 ng/mL lower than those able to transfer independently. A regression analysis performed in residents unable to transfer independently (less likely to be exposed to the sun) demonstrated that the average increase in 25-OH-D level per 100 IU of D(3) in a 70-kg resident was 2.1 ng/mL versus 1.8 ng/mL for vitamin D(2).


CONCLUSIONS
Nursing home residents should receive at least 800-1000 IU of D(3) per day in an effort to maintain optimal vitamin D levels.
Drinka
Paul J
PJ
Wisconsin Veterans Home, King, WI 54946, USA. Paul.Drinka@dva.state.wi.us
Krause
Peggy F
PF
Nest
Lori J
LJ
Goodman
Brian M
BM
D000368:Aged; D000369:Aged, 80 and over; D050071:Bone Density Conservation Agents / Q000008:administration & dosage*; D002112:Calcifediol / Q000097:blood / Q000172:deficiency; D002762:Cholecalciferol / Q000008:administration & dosage*; D003430:Cross-Sectional Studies; D016903:Drug Monitoring; D004872:Ergocalciferols / Q000008:administration & dosage*; D005260:Female; D015577:Geriatric Assessment; D005919:Glomerular Filtration Rate; D006801:Humans; D007674:Kidney Diseases / Q000150:complications; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D009735:Nursing Homes; D010281:Parathyroid Hormone / Q000097:blood; D012044:Regression Analysis; D012720:Severity of Illness Index; D013472:Sunlight; D016896:Treatment Outcome; D014728:Veterans; D014808:Vitamin D Deficiency / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control*; D014922:Wisconsin / Q000453:epidemiology
D050071:Bone Density Conservation Agents; D004872:Ergocalciferols; D010281:Parathyroid Hormone; D002762:Cholecalciferol; D002112:Calcifediol