How strong is your immune system? If your initial thought is some iteration of: Uh, I’m not sure, you’re certainly not alone. It can be difficult to know how well your body’s natural defenses are operating—unless, you know, you get sick.
However, according to our director of scientific affairs, Ashley Jordan Ferira, Ph.D., RDN, on the mindbodygreen podcast, a few quick tests can help give you some insight. Below, she explains exactly how to tell if your immune system is in tiptop shape:
1. Complete blood count.
“A complete blood count (CBC) would for sure be [your] No. 1 baseline to see if there’s any dysfunction with any of your major classes of immune cells,” says Ferira. While this test measures all different features of your blood, including red blood cells, white blood cells, platelets, hemoglobin, and hematocrit, the white blood cell portion can be super telling: Different types of white blood cells (like neutrophils, lymphocytes, basophils, etc.) can shed light on your immune response.
Says Ferira: “We know, for instance, neutrophils increase when you have an infection.” That said, a CBC test may be able to highlight these different responses and offer up some information.
2. Metabolic health & inflammation markers.
“Metabolic health and inflammation—these mechanisms go hand in hand with immunity,” Ferira continues. It’s a topic we’ve discussed at length here at mbg: Immunity and metabolic health are intertwined, as your immune system acts as a sensor of your metabolic state.
That’s why Ferira suggests checking up on metabolic health markers—you know, waist circumference, blood pressure, blood sugar, lipids, and a few others you can find listed here.
“In the inflammation realm, [test for] things like C-reactive protein,” she adds, as well as serum ferritin, and D-dimer; these unique labs might be able to signal your inflammatory response.*
Daily immunity shield to strengthen your body’s natural defenses*
Next up, Ferira touts the importance of nutrition status. Namely, vitamin D levels: We likely don’t have to remind you about the link between vitamin D and immunity* (the fat-soluble vitamin and hormone plays an important role in immune function; see here for a handy guide), and Ferira says a 25-hydroxyvitamin D blood test can gauge your levels.
“[It’s] the biomarker for your vitamin D status,” she notes. “If you don’t know your baseline, I encourage you to get a serum 25-hydroxyvitamin D test.”
A less commonly tested—but still significant—measurement would be your vitamin C levels. “That’s a plasma level of ascorbic acid,” Ferira explains. As you may know, vitamin C plays a large role in immunity: Specifically, it promotes multiplication of lymphocytes (remember, that’s a type of white blood cell) to combat foreign invaders in the body.* Vitamin C also helps neutrophils (another white blood cell we mentioned earlier) “eat” and destroy bad microbes.*
Finally, we have zinc: The trace mineral is critical for the development and function of many immune cells in your innate (neutrophils, macrophages, and natural killer cells) and adaptive immune (B-cells and T-cells) responses.* To test your natural zinc levels, Ferira recommends asking for a serum test.
If you’re wondering how well your immune system is operating, these markers can shed some light on your body’s natural defenses. Of course, it’s often not easy (or realistic) to head to the doctor every time you’re curious about your immune status—but these lab tests can offer you a baseline at your annual or periodic checkups. As Ferira adds, “Taken together, I think [these] would give a stellar picture of immune health and some levers that you could pull to improve your immune status.”*
If you are pregnant, breastfeeding, or taking medications, consult with your doctor before starting a supplement routine. It is always optimal to consult with a health care provider when considering what supplements are right for you.