No effect of ultraviolet radiation on blood pressure and other cardiovascular risk factors.
J Hypertens. 2011 Jun 30.
Scragg R, Wishart J, Stewart A, Ofanoa M, Kerse N, Dyall L, Lawes CM.
aSchool of Population Health, University of Auckland bEpsom, Auckland, New Zealand.
OBJECTIVES:
Recent epidemiological studies have reported inverse associations between vitamin D status and blood pressure. The study aim is to determine if exposure to ultraviolet B radiation, which synthesizes vitamin D, lowers blood pressure, compared with ultraviolet A radiation.
METHODS:
Men and women (n?=?119) with low vitamin D levels [serum 25-hydroxyvitamin D 25(OH)D <50?nmol/l], completed a randomized clinical trial carried out during winter. Blood pressure was measured for 12-14?h with an ambulatory monitor at baseline and 12 weeks. In between, participants received 24 whole body exposures of either ultraviolet B (n?=?58) or ultraviolet A (n?=?61) over 12 weeks.
RESULTS:
Mean (SD) 25(OH)D increased from
- 43.7 (9.7) to 92.6 (16.9) nmol/l in the ultraviolet B arm after 12 weeks, and from
- 45.4 (9.2) to 64.9 (11.3) nmol/l in the ultraviolet A arm.
However, mean blood pressure, which was similar for the ultraviolet B and ultraviolet A at baseline (134.9/79.2 vs. 132.9/77.8?mmHg; P?=?0.59 and 0.56, respectively), did not change from baseline to 12 weeks in either group. The mean change 95% confidence interval (CI) in blood pressure over this period in the ultraviolet B group compared with the ultraviolet A group was -2.2 (-7.8, 3.3)?mmHg for systolic (P?=?0.42) and -2.7 (-6.5, 1.0)?mmHg for diastolic (P?=?0.15).
CONCLUSION:
Exposure to ultraviolet B did not lower blood pressure. Our results suggest that if vitamin D protects against cardiovascular disease, it involves some mechanism other than blood pressure.
PMID: 21720260
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Strange
- UVA increased vitamin D levels from 18 ng to 26 ng
Not Strange
- Increasing vitamin D levels from 17 ng to 34 ng did not change blood pressure
- probably need at least 50 ng to make a difference
See also VitaminDWiki
- All hypertension patients should have vitamin D levels measured – 2010
- Overview Cardiovascular and vitamin D
- Meta-analysis found hypertension reduced with vitamin D – Dec 2010
- Hypertension more likely with less vitamin D - Dec 2010 authors work for Kaiser Permanente
- Vitamin D reduced blood pressure in random controlled trials – Nov 2010
- Systolic hypertension 4X more likely if low on vitamin D 14 years before – Nov 2010
- Hypertension and vitamin D many papers
- Does vitamin D deficiency cause hypertension? 2010 with PDF
- Systolic hypertension 4X more likely if low on vitamin D 14 years before – Nov 2010
- 11 ng less vitamin D increases hypertension probability by 14 percent – Nov 2010
- All items in category Hypertension
- Less than 15ng were 3X more likely to be hypertensive - 2010.pdf
- 25 percent of racial disparity in Blood Pressure is due to Vitamin D – April 2011
- Link between vitamin D and hypertension not yet completely understood – April 2011