Vitamin D Therapy in Individuals with Pre-Hypertension or Hypertension: The DAYLIGHT Trial

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

*Corresponding author for this work

Research output: Contribution to journalArticle


METHODS AND RESULTS—: A double-blind, randomized controlled trial was conducted at 4 sites in the United States. We enrolled 534 individuals aged 18 to 50 years with low vitamin D status (25-hydroxyvitamin D levels ≤ 25 ng/ml) and systolic blood pressure 120-159 mm Hg. Participants were randomized to high-dose (4,000 IU/day) versus low-dose (400 IU/day) oral vitamin D3 for 6 months. The primary endpoint was change in mean 24-hour systolic blood pressure. Secondary endpoints 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 fifty-five participants (85%) had at least one 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 endpoint (change in mean 24-hour systolic blood pressure, -0.8 mm Hg versus -1.6 mm Hg in the high-dose and low-dose arms, p=0.71) or in any of the secondary endpoints. Further, 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 pre-specified subgroups.

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.

CONCLUSIONS—: Vitamin D supplementation did not reduce blood pressure in individuals with pre- 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
StateAccepted/In press - Nov 3 2014

ASJC Scopus subject areas

  • Physiology (medical)
  • Cardiology and Cardiovascular Medicine

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    Arora, P., Song, Y., Dusek, J., Plotnikoff, G., Sabatine, M., Cheng, S., Valcour, A., Swales, H., Taylor, B., Carney, E., Guanaga, D., Young, J. R. R., Karol, C., Torre, M., Azzahir, A., Strachan, S. M. M., OʼNeill, D. C., Wolf, M., Harrell, F., ... Wang, T. J. J. (Accepted/In press). Vitamin D Therapy in Individuals with Pre-Hypertension or Hypertension: The DAYLIGHT Trial. Circulation.