Healthy people with higher vitamin D levels in their blood may enjoy several benefits, apart from improved bone health, researchers from Boston University School of Medicine reported in PLOS ONE.

The authors explained that their study found that higher vitamin D levels in healthy people have a considerable impact on the genes that are involved in several biologic pathways linked to infectious diseases, autoimmune diseases, cardiovascular disease and cancer.

Previous studies have demonstrated that excessively low vitamin D levels are associated with a higher risk of developing the diseases mentioned above. The researchers emphasized that their findings provide further evidence that healthy people who improve their vitamin D status have significantly better immunity and a reduced risk of several diseases.

Vitamin D is unique

There are two ways we can obtain vitamin D:
  • It can be ingested - eaten or drunk
  • It can be synthesized by the body when our skin is exposed to the sun
The kidneys and the liver then convert it to a form that is usable by the body.

A person's vitamin D level (vitamin D status) is gauged by measuring the blood level of 25-hydroxyvitamin D. When levels go below 20 nanograms per milliliter (ng/mL) the person has vitamin D deficiency. Vitamin D deficiency can cause rickets, other musculoskeletal diseases, and further problems.

Recent studies have linked vitamin D insufficiency (between 21-29 ng/mL) and vitamin D deficiency (<20 ng/mL) to a higher risk of developing:
  • Cancer
  • Autoimmune diseases
  • Infectious diseases
  • Type 2 diabetes
  • Cardiovascular diseases
This latest, double-blind, randomized, single-site pilot trial included eight healthy adult males and females who were either vitamin D insufficient or deficient when the trial began:
  • Three participants were given 400 International Units (IUs) of vitamin D per day
  • Five participants were given 2,000 IUs per day
This continued for two months. The researchers collected samples of white blood cells - immune cells - at the beginning and the end of the two-month period. Over 22,500 genes were investigated from the samples to determine whether their activity had increased or decreased after the vitamin D intake.

At the end of the trial:
  • Those in the 2000 IUs group achieved a vitamin D status of 34 ng/mL (considered sufficient)
  • In the 400 IUs group their vitamin D status was 25 ng/mL (insufficient)

291 genes were significantly altered

The gene expression analysis showed "statistically significant alterations in the activity of 291 genes".

When the genes were analyzed further, the scientists found that their biologic functions were related to 160 biologic pathways associated with cardiovascular disease, infectious diseases, autoimmune diseases and cancer.

After examining elements of gene response, or sequences of DNA bases that interact with vitamin D receptors to control gene expression, the researchers also found new genes related to vitamin D status.

To make sure that their findings were accurate, they looked at 12 genes which are known not to have alterations in their level of expression - they remained stable throughout the two months.

Michael F. Holick, PhD, MD, professor of medicine, physiology and biophysics at BUSM, said:

"This study reveals the molecular fingerprints that help explain the non-skeletal health benefits of vitamin D. While a larger study is necessary to confirm our observations, the data demonstrates that improving vitamin D status can have a dramatic effect on gene expression in our immune cells and may help explain the role of vitamin D in reducing the risk for CVD, cancer and other diseases."

This research was supported by a pilot grant from the National Institutes of Health's Clinical Translational Science Institute under grant award # UL-1-RR-25711.

Vitamin D - A popular subject to study

Over the last twenty years, there have been hundreds of studies on vitamin D which have been published in peer-reviewed academic journals. Below are examples of some studies: Written by Christian Nordqvist