title: Long-term high-dose vitamin D3 supplementation and blood pressure in healthy adults: a randomized controlled trial.
abstract: Previous randomized controlled trials of vitamin D supplementation and blood pressure (BP) mainly have given vitamin D for short periods (<6 months) or at low doses (400 IU per day). This study aims to determine whether long-term high-dose vitamin D taken for 18 months lowers BP. Adults were recruited from a healthcare organization or university into a double-blind controlled trial and randomized to receive either vitamin D3 200 000 IU for 2 months followed by 100 000 IU monthly up to 18 months (n=161) or placebo (n=161). BP was measured at baseline, 5, and 18 months. Subjects had a mean (SD) age of 47.6 (9.7) years, 75% were women, and 94% were of European ancestry (white). Mean (SD) 25-hydroxyvitamin D3 changed from 73 (22) nmol/L at baseline to 124 (28) nmol/L at 18 months in the vitamin D group, and from 71 (22) nmol/L to 56 (22) nmol/L in the placebo group. Mean BP was similar for the vitamin D and placebo groups at baseline (123.4/76.3 versus 122.6/75.6 mm Hg; respectively). The mean change (95% confidence interval) in BP at 18 months minus baseline in the vitamin D group compared with placebo group was -0.6 (-2.8 to 1.6) mm Hg for systolic (P=0.61) and 0.5 (-1.1, 2.2) mm Hg for diastolic (P=0.53). Long-term vitamin D supplementation, which increased mean 25-hydroxyvitamin D3 concentration >100 nmol/L for 18 months, had no effect on systolic or diastolic BP in predominantly white, healthy adults without severe vitamin D deficiency. Beneficial effects on BP cannot be ruled out for other populations.
authors: From the School of Population Health, University of Auckland, Auckland, New Zealand (R.S., A.W.S.); Department of Pathology, University of Otago, Christchurch, New Zealand (S.S., L.C.J., S.T.C., C.M.F., D.R.M.); Preventive and Social Medicine, University of Otago, Dunedin, New Zealand (P.C.P.); and Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (C.A.C.). r.scragg@auckland.ac.nz.
authors: Robert
authors: R
authors: Scragg
authors: From the School of Population Health, University of Auckland, Auckland, New Zealand (R.S., A.W.S.); Department of Pathology, University of Otago, Christchurch, New Zealand (S.S., L.C.J., S.T.C., C.M.F., D.R.M.); Preventive and Social Medicine, University of Otago, Dunedin, New Zealand (P.C.P.); and Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (C.A.C.).
authors: Sandy
authors: S
authors: Slow
authors: From the School of Population Health, University of Auckland, Auckland, New Zealand (R.S., A.W.S.); Department of Pathology, University of Otago, Christchurch, New Zealand (S.S., L.C.J., S.T.C., C.M.F., D.R.M.); Preventive and Social Medicine, University of Otago, Dunedin, New Zealand (P.C.P.); and Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (C.A.C.).
authors: Alistair W
authors: AW
authors: Stewart
authors: From the School of Population Health, University of Auckland, Auckland, New Zealand (R.S., A.W.S.); Department of Pathology, University of Otago, Christchurch, New Zealand (S.S., L.C.J., S.T.C., C.M.F., D.R.M.); Preventive and Social Medicine, University of Otago, Dunedin, New Zealand (P.C.P.); and Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (C.A.C.).
authors: Lance C
authors: LC
authors: Jennings
authors: From the School of Population Health, University of Auckland, Auckland, New Zealand (R.S., A.W.S.); Department of Pathology, University of Otago, Christchurch, New Zealand (S.S., L.C.J., S.T.C., C.M.F., D.R.M.); Preventive and Social Medicine, University of Otago, Dunedin, New Zealand (P.C.P.); and Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (C.A.C.).
authors: Stephen T
authors: ST
authors: Chambers
authors: From the School of Population Health, University of Auckland, Auckland, New Zealand (R.S., A.W.S.); Department of Pathology, University of Otago, Christchurch, New Zealand (S.S., L.C.J., S.T.C., C.M.F., D.R.M.); Preventive and Social Medicine, University of Otago, Dunedin, New Zealand (P.C.P.); and Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (C.A.C.).
authors: Patricia C
authors: PC
authors: Priest
authors: From the School of Population Health, University of Auckland, Auckland, New Zealand (R.S., A.W.S.); Department of Pathology, University of Otago, Christchurch, New Zealand (S.S., L.C.J., S.T.C., C.M.F., D.R.M.); Preventive and Social Medicine, University of Otago, Dunedin, New Zealand (P.C.P.); and Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (C.A.C.).
authors: Christopher M
authors: CM
authors: Florkowski
authors: From the School of Population Health, University of Auckland, Auckland, New Zealand (R.S., A.W.S.); Department of Pathology, University of Otago, Christchurch, New Zealand (S.S., L.C.J., S.T.C., C.M.F., D.R.M.); Preventive and Social Medicine, University of Otago, Dunedin, New Zealand (P.C.P.); and Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (C.A.C.).
authors: Carlos A
authors: CA
authors: Camargo
authors: From the School of Population Health, University of Auckland, Auckland, New Zealand (R.S., A.W.S.); Department of Pathology, University of Otago, Christchurch, New Zealand (S.S., L.C.J., S.T.C., C.M.F., D.R.M.); Preventive and Social Medicine, University of Otago, Dunedin, New Zealand (P.C.P.); and Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (C.A.C.).
authors: David R
authors: DR
authors: Murdoch
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D002762:Cholecalciferol / Q000008:administration & dosage*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D016896:Treatment Outcome; D014815:Vitamins / Q000008:administration & dosage; D055815:Young Adult
chemical_list: D014815:Vitamins; D002762:Cholecalciferol
keywords: European Continental Ancestry Group; blood pressure; hypertension; randomized controlled trial; therapeutic use