Vitamin D - To Supplement or Not To Supplement?

Vitamin D has been a hot topic for the better part of two decades now. It’s been hailed as a cure-all vitamin used for everything from heart disease to diabetes and everything in between. Previously, I had written about the benefits of vitamin D in my article titled, How To Feel Vitamin “D”errific!

Now, I provide an update on vitamin D, specifically as it pertains to vitamin D deficiencies and who should supplement in such cases. These findings are based on the latest research.
 

SUPPLEMENTING TO TREAT VITAMIN D DEFICIENCY

Two large-scale, systemic reviews published earlier this month have provided some keen insight on this topic and may just change the rules when it comes to supplementing with vitamin D.

Vitamin D Status and Ill Health: A Systematic Review (published December 6th, 2013)
The first study titled “Vitamin D Status and Ill Health: A Systemic Review” was published in The Lancet Diabetes and Endocrinology  journal [1]. Researchers in this review analyzed 290 observational studies looking at vitamin D status and chronic disease incidence and 172 randomized trials on health outcomes following vitamin D supplementation.

In the observational data set in this review, a majority of studies showed a moderate to high inverse association between vitamin D levels and various chronic diseases (cardiovascular disease, obesity, diabetes, infectious diseases, multiple sclerosis, mood disorders, etc.). In other words, higher blood levels of vitamin D were associated with fewer chronic diseases in people, while lower blood levels of vitamin D (vitamin D deficiencies) were associated with more chronic diseases in people.

What can one derive from this? Simply, that there is an association between a person’s blood levels of vitamin D and chronic disease prevalence. This does not necessarily mean that a lack of vitamin D causes these chronic diseases. It only means that there is a correlation between the two. Cause and effect cannot be directly established in such cases, even though valuable insights are obtained.

To better understand the role of vitamin D in these chronic diseases, we need to look at data from the set of randomized trials in this study. The randomized trials are able to better tell us whether or not supplementing with vitamin D (and thus correcting the deficiency) actually leads to better overall health by reducing the occurrence of chronic diseases.

So, what did they find? Supplementing with vitamin D did not produce better results in terms of disease occurrence, even when individuals were diagnosed with a vitamin D deficiency before beginning supplementation. There was, however, one exception to this rule. Elderly patients (mainly women) did experience a slight reduction in all-cause mortality (i.e. death) after supplementing with vitamin D 800 IU per day. This data may come as a surprise to many in the scientific and medical community, as it was previously thought that all persons with a vitamin D deficiency (25(OH)D level < 20 ng/ml) should be taking a vitamin D supplement to correct the deficiency [2].

Read rest of article here.