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

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• 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