Can Chromatography Detect Vitamin D Levels?

Believe it or not — it is possible that we don’t get enough sunlight in the UK. I know, who would have thought. But this has a serious impact on us. It can lead to a deficiency in one of the crucial nutrients we need — vitamin D. Let’s take a closer look at the nutrient and see how levels can be accurately checked in the lab.

Vitamin D — made in the sun

Vitamin D is a group of fat-soluble steroids that humans use to help increase the absorption of minerals including calcium and zinc. Two important members of the group are ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). It is possible to get these vitamins from our diet — but you’d have to eat an awful lot of mushrooms and soy milk. The main source of vitamin D in humans is the action of sunlight on our bodies.

During the summer months (April to September) we can get enough vitamin D by exposing our skin to the sun when the sun is high in the sky. It is the UVB rays that our bodies need to make vitamin D, so sitting indoors behind a window is no good. For most people, the required amount of sunlight can be obtained well before we burn. But, there are other factors that affect individuals and means that no simple message can be given.

Should you top up your tan?

Unfortunately, sunlight also causes damage to our skin and sunburn could be the least of your worries as skin cancer prevalence is increasing. And although we can store vitamin D — as it is a fat-soluble vitamin — who gets the chance to sit out in the midday sun anyhow.

In the UK, the winter sun doesn’t contain enough UVB to keep us going, and anyhow we are usually all wrapped up. So, vitamin D deficiency is a problem that most people don’t know they have. That is why the UK government recommends people take Vitamin D supplements. Deficiency can lead to problems including rickets and painful bones. But how do you check your levels?

Vitamin D testing

The simple way for a doctor to check your vitamin D levels is with a blood test. However, there is a great deal of debate about what the optimal level of vitamin D is. Vitamin D is not usually measured directly in a blood test, rather the concentration of 5-hydroxyvitamin D [25(OH)D] is measured typically using chromatography. 25(OH)D is a metabolite that is made in the liver during the production of vitamin D.

Liquid chromatography is the preferred method for vitamin D analysis. HPLC and HILIC are techniques used to analyse for metabolites produced in the body as discussed in the article, Development of a Hydrophilic Interaction Liquid Chromatography Retention Model for Procainamide Tagged N-linked Glycans.

So, do you get the right amount of the sunshine vitamin?