Vitamin D Heart Health FAQ

All in all, the vast majority of people can take vitamin D without worry about interactions with drugs. Of course, there are always peculiar or unique situations that should always be discussed with your doctor, who should know your health situation best.

We live in Florida. My husband and I spend much of our day outdoors, since we are both retired.

I figure that our outdoor lifestyle means that we probably don't need to take vitamin D. Do you agree?

No, I do not agree. Since you and your husband are retired, I assume that you are somewhere in your 60s or older. This means that much of the capacity for activation of vitamin D in your skin has been lost.

An informative 2005 study performed in Miami residents over age 65 showed that blood levels of vitamin D were clearly deficient during winter, with blood levels ranging around 25 ng/ml. But they were little better in summer, ranging from 25 ng/ml in women to 31 ng/ml in men (mean values). On average, both men and women raised blood vitamin D a meager 14% from summer to winter. Obviously, it's probably somewhat worse the farther north we go.

Therefore, by not checking and supplementing vitamin D, it is highly likely that you and your husband are deficient year round, even in Florida, despite sun exposure.

The message: Get vitamin D checked, but don't be surprised if your level is low; it's the rule, rather than the exception.

I take fish oil capsules for heart health. This means I don't have to take vitamin D, right?

Nope, sorry. Fish oil is fish oil containing omega-3 fatty acids, EPA and DHA; vitamin D is vitamin D.

Perhaps the confusion arises from the fact that cod liver oil contains both omega-3 fatty acids and vitamin D. Much vitamin D is also made from fish oil, but the two components are separated to yield fish oil without vitamin D, and vitamin D without omega-3 fatty acids. Both exert their own independent benefits. In my view, both are best taken separately.

Why not just take cod liver oil and get both omega-3 fatty acids and vitamin D at the same time?

Some people do indeed choose this route. However, it's not my first choice since I find it difficult to change the dose of omega-3 fatty acids or vitamin D independently, not to mention that vitamin A is also present. Because the doses of vitamin D I advocate in my patients often ranges in the 4000-10,000 units per day, occasionally higher, this would lead to taking excessive, potentially toxic levels of vitamin A from a cod liver oil preparation.

Is it possible to take too much vitamin D?

Yes, indeed it is.

Vitamin D toxicity is evidenced by a rise in blood calcium to the abnormally high range, but it is rare if you and your doctor are monitoring blood levels of vitamin D. Vitamin D authorities differ to some degree on what level of vitamin D in the blood could begin to account for toxic effects, with some proposing that levels as low as 80 ng/ml, while others propose as high as 150 ng/ml.