2021 Guide To Vitamin D Testing & Supplementation

Yes, Vitamin D plays a significant role in metabolizing our bones and minerals. Vitamin D testing and supplementation have been an area of hot debate.
In fact, it is such a hot topic that researchers have attempted to tackle this head-on.

But what in 2021 makes Vitamin D such a hot topic?

For one, low levels of Vitamin D lead directly to poor health outcomes such as osteomalacia and rickets. 

Beyond that, there’s a global Vitamin D deficiency, leaving people all over the world open to potential ailments and diseases.

With this all in mind, it’s no wonder that Vitamin D testing and supplementation are growing in importance. These areas have been well researched, but this article intends to break them down into the simplest terms. 

Measuring Vitamin D Levels and What They Mean

With Vitamin D testing, levels are defined as serum 25(OH)D levels and measured in units of nmol/L.

Ideally, serum 25(OH)D levels should be at 50 nmol/L and above. Whereas anything below 25-30 nmol/L is a cause for concern.

We’ll then point out that a serum 25(OH)D above 375 nmol/L can cause vitamin D intoxication--but this is very rare. 

Lastly, know that levels peak at the end of summer and at their lowest by the end of winter. 

Confusion Surrounding Vitamin D Testing

Physicians don’t hesitate with a Vitamin D test when it seems like a patient has rickets or osteomalacia. The waters are much murkier beyond these conditions, though.

For instance, there are many disagreements on whether hyper/hypoparathyroidism and chronic kidney disease patients should receive Vitamin D testing. 

Also, osteoporosis patients frequently receive Vitamin D testing. But it’s not always a go-to method for these types of at-risk individuals. Namely, field professionals think that measuring serum 25(OH)D is too expensive. And there’s no universal gold standard for testing with mass spectrometry.

Vitamin D Supplementation

Micrograms (µg) are used to measure Vitamin D intake. 

It’s estimated that by supplementing 2.5 µg of vitamin D per day, someone’s serum 25(OH)D concentrations could rise by 2.5–5 nmol/L over time. Here are some further considerations:

• Often, improvements caused by supplementation flatten out at higher intakes.
• According to several studies, people with higher BMI or lower baseline Vitamin D levels tend to experience the highest increases. 
  

When on a Vitamin D supplementation regime, take at least 8 weeks after your first dose before re-measuring. That’s how long is needed to reach a steady-state. Some studies even claim you might need 12 weeks or longer to get to a steady state. 

While Vitamin D supplementation programs can be done weekly or monthly, many experts believe daily doses are the best approach. Partially, this is due to Vitamin D only having a one-day halflife.

Plus, some studies report adverse effects with intermittent high doses, such as patients experiencing falls and fractures.

Taking Charge of Your Own Vitamin D Testing.

Doctors won’t be too forthcoming with Vitamin D testing unless it’s a reactive measure to rickets, osteomalacia, or maybe osteoporosis. 

But confusion amongst medical professionals doesn’t need to stop you from being proactive.

Don’t wait until you’re suffering from a health condition to stay on top of your Vitamin D levels. Taking charge and monitoring serum 25(OH)D (with home tests, for instance) can vastly improve your long-term health and well-being. 

With only one measurement, you’ll have an indicator for future levels, even if both tests are years apart. It’s similar to monitoring blood lipids and blood pressure. 

As such, assume that more consistent monitoring gives you the information that helps keep your levels close to their peak and far from the danger zone. You’ll know if there’s a need for adjustments in your supplementation or if you’re already in a good spot and just need to maintain.