Several studies have shown that ruptured aneurysms in the head (intracranial aneurysms) are much more common among those with low blood levels of vitamin D. This strong relationship held up after adjusting for other conditions.

One study looked at 160 patients with an intracranial aneurysm and 33 control patients without an aneurysm, matched exactly for age, sex, and other associated conditions. The researchers found that the relationship to having a low vitamin D level held up, and did so as a lone marker.

It also appears to hold true for other types of aneurysms, such as aortic aneurysms. A mouse study used to discover a link to vitamin D levels and aneurysm rupture found that the vitamin D affected several factors in the wall of blood vessels that prevented development of the aneurysm and its subsequent rupture.

To help prevent aneurysms — along with many other health benefits — it’s important to keep your vitamin D level at least at 65 ng/mL but slightly below 100 ng/mL. An oral dose of vitamin D3 of less than 2,000 IU will not raise the blood level appreciably.

Low vitamin D3 levels begin in childhood. I asked a pediatrician friend who had the largest pediatric practice in his state how many of his patients (he tested them all) had a vitamin D3 level below normal. He said, “All of them.”