For some patients, the vitamin could even replace implantable cardioverter defibrillators as a primary treatment of heart failure. Unlike ICDs, vitamin D is cheap, causes no side effects and doesn't require surgery.
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The study is still ongoing, but the early results are promising for the roughly 23 million people around the world affected by heart failure.
For a natural boost, the human skin produces vitamin D during sun exposure. The "sunshine vitamin" can also be found in oily fish and eggs.