Vitamin D therapy in individuals with prehypertension or hypertension the DAYLIGHT trial

Pankaj Arora, Yanna Song, Jeffery Dusek, Gregory Plotnikoff, Marc S. Sabatine, Susan Cheng, Andre Valcour, Heather Swales, Beth Taylor, Erin Carney, Derek Guanaga, Joseph R. Young, Courtney Karol, Michael Torre, Atum Azzahir, Semerit M. Strachan, Dillon C. O'Neill, Myles Wolf, Frank Harrell, Christopher Newton-ChehThomas J. Wang

Research output: Contribution to journalArticlepeer-review

99 Scopus citations


Background-A large body of epidemiological and experimental evidence suggests that vitamin D deficiency may promote hypertension. This raises the possibility that vitamin D supplementation could be a simple intervention to reduce blood pressure, but data from prospective, randomized trials are limited. Methods and Results-A double-blind, randomized, controlled trial was conducted at 4 sites in the United States. We enrolled 534 individuals 18 to 50 years of age with low vitamin D status (25-hydroxyvitamin D levels ≤25 ng/mL) and systolic blood pressure of 120 to 159 mm Hg. Participants were randomized to high-dose (4000 IU/d) versus low-dose (400 IU/d) oral vitamin D3 for 6 months. The primary end point was change in mean 24-hour systolic blood pressure. Secondary end points included change in ambulatory diastolic blood pressure and clinic systolic and diastolic blood pressures. The median age was 38 years, and 62% of participants were men. Forty-six percent of participants were white, and 48% were black. The median 25-hydroxyvitamin D level at baseline was 15.3 ng/mL. Four-hundred fiftyfive participants (85%) had at least 1 follow-up blood pressure measurement; 383 participants (72%) completed the full 6-month study. At the end of the study, there was no significant difference in the primary end point (change in mean 24-hour systolic blood pressure, -0.8 versus -1.6 mm Hg in the high-dose and low-dose arms; P=0.71) or in any of the secondary end points. Furthermore, there was no evidence of association between change in 25-hydroxyvitamin D and change in 24-hour systolic blood pressure at 6 months (Spearman correlation coefficient, -0.05, P=0.34). Results were consistent across prespecified subgroups. Conclusions-Vitamin D supplementation did not reduce blood pressure in individuals with prehypertension or stage I hypertension and vitamin D deficiency. Our findings suggest that the association between vitamin D status and elevated blood pressure noted in observational studies is not causal.

Original languageEnglish (US)
Pages (from-to)254-262
Number of pages9
Issue number3
StatePublished - 2015
Externally publishedYes


  • Blood pressure
  • Dietary supplements
  • Hypertension
  • Vitamin D deficiency

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)


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