How Vitamin D Prevents Heart Problems

David Juan, MD

Vitamin D is a friend to your heart.

In one study with 18 adults with high blood pressure, exposure to ultraviolet B radiation three times a week for a total of six weeks during the winter months increased vitamin D levels by 162% and significantly reduced systolic and diastolic blood pressure levels. That is just the tip of the evidential iceberg.

In another study, 148 postmenopausal women aged 74 years were given either 1,200 mg calcium plus 800 IU vitamin D3 or just 1,200 mg calcium daily for two months.

It led to this:
-- Calcium and vitamin D had the biggest drop in systolic blood pressure, by 9.3%.
-- 81% of people in the vitamin D-calcium group had significant drops in systolic blood pressure compared to 47% of the calcium group.
-- There was no difference in the diastolic blood pressure in either group.

Vitamin D deficiency has been linked to various cardiovascular diseases. For instance, patients with heart attacks tend to have lower vitamin D levels. And patients with stroke and congestive heart failure tend to have much lower levels.

Do vitamin D supplements lower the risk of such heart diseases? Unfortunately, the vitamin D dosages used in the replacement studies are now generally considered inadequate. In a large population study, over 36,000 postmenopausal women were given calcium carbonate with only 200 IU of vitamin D daily. Not surprisingly, this study failed to show any significant differences between the calcium/vitamin D treated group and the placebo group in terms of heart attacks or stroke.

In a meta-analysis involving 57,311 individuals that examined the effect of vitamin D supplementation (300 IU to 2,000 IU, or average 538 IU daily) on overall mortality (mostly due to cancer, cardiovascular disease and diabetes), French researchers reported that even ordinary doses of vitamin D supplements led to a decrease in overall mortality.

A recent review found that chronic and often decades-long vitamin D deficiency can help trigger ischemic heart disease, hypertension, heart failure, metabolic syndrome and other severe heart issues. They believe that correcting vitamin D levels could affect death rates from the most common cardiovascular diseases.

Sources:
1. Krause, R., et al., "Ultraviolet B and blood pressure," Lancet, 1998; 352: 709-710.
2. Zittermann, A., et al., "Low vitamin D status: a contributing factor in the pathogenesis of congestive heart failure," J. Am. Coll. Cardiol., 2003; 41: 105-112.
3. Pfeifer, M., et al., "Effects of a Short-Term Vitamin D3 and Calcium Supplementation on Blood Pressure and Parathyroid Hormone Levels in Elderly Women," J. Clin. Endo. Met., 2001; 86: 1,633-37.
4. Wallis, D.E., et al. "The 'Sunshine Deficit' and Cardiovascular Disease" Circulation, 2008; 118: 1,476-85.
5. Autier, P., and Gandini, S., "Vitamin D Supplementation and Total Mortality," Arch. Int. Med., 2007; 167: 1,730-37.
6. Hsia, J., et al., "Calcium/vitamin D supplementation and cardiovascular events," Circulation, 2007; 115: 846-854.
7. Scragg, R., et al: Myocardial infarction is inversely associated with plasma 25-hydroxylvitamin D3 concentrations: a community-based study," Int. J. Epidemiol., 1990; 19: 559-563.
8. Poole, K.E., et al., "Reduced vitamin D in acute stroke" Stroke, 2006; 37: 243-245.

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