Laboratory Focus: Serum Vitamin D

Do you need to supplement with vitamin D?  Today I want to talk about a very simple blood test that often gets overlooked, but is an important tool when it comes to evaluating our Vitamin D status.  This test is known as Serum Vitamin D. 

The winter months are a dreary and dark time.  We are exposed to fewer hours of daylight during the winter months, and this results in less sun exposure.  Vitamin D is converted to it’s active form in our blood when our skin is exposed to the sun’s rays.  This active form of Vitamin D is important for many different reasons, including the support of our immune system as well as muscle and bone health.  We also addressed the importance of Vitamin D during flu season here.  In addition to these systems, Vitamin D also plays a defining role in our mood.

Seasonal Affective Disorder

When we have insufficient skin exposure to direct sunlight, and our blood levels of active Vitamin D inevitably decline, this can result in Seasonal Affective Disorder (SAD).   Seasonal Affective Disorder is a type of depression that occurs during the same season each year.  Getting direct sun exposure during the winter months  (5-20 minutes, 2 times a week) can help to increase Vitamin D, improve our mood, and prevent against developing SAD.  Supplementing with vitamin D can also be beneficial when it comes to treating this concern.

But how much Vitamin D we need?

Laboratory Serum Vitamin D

Our Vitamin D status, and possible insufficiency, can be determined with a very simple and important test, known as Serum Vitamin D.  Serum is the fluid that remains when coagulants and other materials have been removed from your blood.  Vitamin D levels can be determined by examining this fluid.  

There are two forms of Vitamin D measured in blood serum:

• 25-hydroxyvitamin D: The inactive form of Vitamin D.
• 1,25-dihydroxyvitamin D: The active form of Vitamin D.

25-hydroxyvitamin D has a longer half-life (remains longer in our blood) and is thus commonly measured to assess and monitor vitamin D status.

Serum Vitamin D is a simple test, with no preparation in advance.  It can be requested by your healthcare provider, including your Naturopathic Doctor.

Who is at risk?

Lower levels of sun exposure are a major reason why some people have low levels of this important vitamin.  That being said, there are some other characteristics that predispose individuals to this condition. 

These include: 

• the elderly,
• those who don’t get enough sun exposure,
• people with darker skin
• people who take certain medications for long periods of time.

If you fall under any of these markers, talk to your health practitioner about your health and Vitamin D supplementation.

Winter is dreary enough! Feeling depressed and low because of seasonal changes can just make things feel more dark.  If you think your vitamin D levels may need a boost, assessing your serum Vitamin D could be beneficial.  Talk to a healthcare professional about whether or not testing and supplementation with Vitamin D is right for you.

Contact Dr. Linda Shih, ND, for more information at Spine Stretch Studio. I look forward to helping you on the road to wellness!

Author: Linda Shih

Dr. Linda Shih, ND is a licensed Naturopathic Doctor who is passionate about preventative and personalized health care, always striving to understand the root cause of her client’s conditions and concerns. She hold an Honors Bachelor of Science Degree from the University of Toronto, a Diploma of Naturopathic Medicine from the Canadian College of Naturopathic Medicine, Toronto, and is a member of the College of Naturopaths of Ontario.
Naturopathic Doctors are considered primary care physicians, and while Dr. Linda Shih maintains a wide scope of practice in her family clinic, she has a special interest in pain management, infertility, as well as digestive concerns.
Using a variety of different modalities, including acupuncture, botanical medicine, and nutritional counseling, Dr. Shih, ND, always aims to help her clients achieve their best health, both now and for the future.