New research published in the Journal of Internal Medicine has found that vitamin D deficiency may be associated with some aspects of orthostatic hypotension.
Orthostatic hypotension is a rapid decline in blood pressure that occurs when standing up. It is caused by blood pooling in the lower areas of the body when a person stands up. It is most common in the oldest-old (defined as 80 years of age or older) with a prevalence of 30% in that age group compared to less than 5% in those younger than 65 years old. Symptoms can include dizziness or feeling lightheaded, or even fainting.
Vitamin D is of interest in orthostatic hypotension because of its suggested role in the cardiovascular system. Vitamin D has been shown to help manage high blood pressure and reduce hardening of arteries. Because of this, researchers in the present study wanted to know if vitamin D deficiency could then be involved in a lack of blood pressure control and subsequent orthostatic hypotension.
To examine this, they looked at a random sample of 329 women who were over the age of 80 years old enrolled in the EPIDOS cohort study. The EPIDOS cohort study was a French multicenter study designed to look at risk factors associated with hip fractures among older women. The cohort took place between 1992 and 1994.
The researchers measured the women’s blood pressure when at rest and then when standing after three minutes of rest. They also took blood samples to evaluate the women’s vitamin D levels.
Around 24% of the women were severely vitamin D deficient (levels less than 10 ng/ml) and of that group, their average level was 8.1 ng/ml.
What the researchers found is that women in this severely deficient group were more likely to have diastolic orthostatic hypotension than women with higher vitamin D levels.
Furthermore, the researchers found that for each 10 ng/ml increase in vitamin D there was a 0.7 mmHg less drop in diastolic blood pressure. When they looked at just the women with clinically defined orthostatic hypotension, they found this same relationship.
“The main result of this population-based study in 329 oldest-old women was that vitamin D deficiency was independently associated with orthostatic hypotension, with an inverse linear relationship between serum [vitamin D] concentration and drop in [diastolic blood pressure] on standing,” the researchers stated.
Might vitamin D’s associated effect on orthostatic hypotension also account for some of vitamin D’s role in preventing falls in the elderly? The researchers speculated.
“Based on our findings, we propose that falls in individuals with [vitamin D] deficiency could also result from orthostatic hypotension and loss of the adaptive response to positional change.”
Since they mainly sampled relatively active older women, their results may not represent older adults in general. Additionally, they only used one measurement of blood pressure drop, meaning they may be an underestimating the strength of the association.
The researchers call for more studies on different and varied populations to see what exactly vitamin D deficiency does to circulatory and neurological mechanisms in those with orthostatic hypotension.