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Increased vitamin D intake may lower blood pressure

January 24, 2014

Consumption of dairy products fortified with vitamin D may reduce systolic and diastolic blood pressure in healthy young women, reports a new study from Spain.

In the randomized controlled trial, blood pressure and cholesterol levels were measured for 165 healthy young women who consumed skimmed milk fortified with vitamin D (200 IU resp. 5 mcg per day) or a placebo (non-fortified milk) for 4 months (1). At the beginning of the study, participants with low serum 25-hydroxyvitamin D concentrations showed higher blood levels of low density lipoprotein-cholesterol, which tended to increase during the study in the placebo group while they were inclined to decrease in the vitamin D group. Systolic and diastolic blood pressure decreased significantly in women receiving the vitamin D fortified milk compared to participants of the placebo group.

The researchers noted that earlier studies have associated low blood vitamin D concentrations with increased risk of major cardiovascular events, cardiovascular mortality, and all-cause mortality (2, 3). However, the associations observed in connection with specific cardiovascular risk markers are not consistent or are contradictory. Vitamin D may influence cardiovascular disease risk by regulating blood pressure through the rennin-angiotensin system (4), by modulating levels of serum lipids (5), or by stimulating insulin secretion (6). In Spain, the recommended daily vitamin D intake is currently set at 200 IU per day for adults while a level of 600 IU has been established in the US. Present data show that mean vitamin D intake in Spain is lower than 200 IU per day and that the consumption of vitamin D fortified dairy products can boost vitamin D supply. Therefore, the promotion of these types of products may have beneficial health effects, as the Spanish population is not aware of the need for extra intake of this vitamin, even in the winter season.

References

  1. Toxqui L. et al. Changes in Blood Pressure and Lipid Levels in Young Women Consuming a Vitamin D-For- tified Skimmed Milk: A Randomised Controlled Trial. Nutrients. 2013; 5:4966-4977.
  2. Leu M. and Giovannucci E. Vitamin D: Epidemiology of cardiovascular risks and events. Best Pract. Res. Clin. Endocrinol. Metab. 2011; 25:633–646.
  3. Saliba W. et al. The risk of all-cause mortality is inversely related to serum 25(OH)D levels. J. Clin. Endocrinol. Metab. 2012; 97:2792–2798.
  4. Vaidya A. and Forman J. P. Vitamin D and hypertension: Current evidence and future directions. Hypertension. 2010; 56:774–779.
  5. Jorde R. and Grimnes G. Vitamin D and metabolic health with special reference to the effect of vitamin D on serum lipids. Prog. Lipid Res. 2011; 50:303–312.
  6. Pittas A. G. et al. The role of vitamin D and calcium in type 2 diabetes. A systematic review and meta-analysis. J. Clin. Endocrinol. Metab. 2007; 92:2017–2029.