The Top 5 Labs Your Doctor Should Test Every Year

As functional nutrition dietitians, clients frequently ask us: "What are the top labs I should be checking every year?" Running labs is so important because, while symptoms can help point you in the direction of what you need to work on, you can’t always “feel” when some lab markers are off. Lab values can provide a deeper look into the internal health issues that are going on, and in turn, allow your team to make the most informed decisions when it comes to your specific diet and lifestyle recommendations. Additionally, collecting labs over time can show trends so you have the opportunity to catch issues as they are developing and before they become a larger issue. Today, we're sharing the top 5 conventional lab markers we recommend getting checked every year.

Lipid Panel

A lipid panel is comprised of a few different markers, all of which look at fats and lipoproteins in your blood. Knowing these numbers can clue you into your risk of developing cardiovascular issues. And the incredible news is that these markers are all greatly affected by diet and lifestyle, meaning that you have the power to improve these markers if any of them come back suboptimal. Cholesterol is an umbrella term for lipoproteins that are needed for various processes in your body such as hormone synthesis and cell membrane formation. LDL cholesterol is the “lousy” cholesterol that you want to see below 100 mg/dL since too much LDL can deposit fats into your arteries. HDL is the “good” cholesterol that you want to see >40 mg/dL if you’re a man and >50 mg/dL if you’re a woman since it can scavenge some of the lipids that LDL deposits, improving arterial health. Finally, triglycerides are a measure of blood fats. A normal level is <150 mg/dL, though it is thought that an optimal level is <100 mg/dL since too many blood fats can lead to arterial hardening. For more on the ranges that we as functional nutrition practitioners recommend staying within (versus conventional recommendations), check out this post!

Blood Sugar Markers

Blood sugar is exactly what it sounds, the level of sugar, or glucose, in your blood. There are a few different markers that provide context when it comes to blood sugar health: fasting glucose, fasting insulin, and Hemoglobin A1C (HbA1C).

• Fasting glucose tells you the level of sugar in your blood after having fasted overnight. This is when sugar should be the lowest, ideally between 70-85 mg/dL, though below 100 mg/dL is considered “normal.” If fasting blood sugar is elevated, it can point to issues with poor blood sugar control or stress.
• Insulin is another great marker to help determine your blood sugar management. Insulin is the hormone that when release, signals cells to take up glucose from the blood. While the range for “normal” insulin is quite high, it is best to keep insulin between 2-7 mIU/L for optimal blood sugar management. A very low insulin level can indicate a that you’re eating a very low carbohydrate or low-calorie diet which may be advisable for some, but can be too stressful for others. A high insulin level indicates that you are likely eating too many carbohydrates or not balancing them well with protein, fat, and fiber, resulting in persistent blood sugar spikes throughout the day.
• HbA1c is a measure of your average glucose over the prior 3 months. The goal is to keep HbA1c between 5.0-5.4%, though the “normal” range is from 4.7-5.6%. While A1c is a very helpful measure, it is not without its flaws. First, if you are pregnant or have issues with blood cells such as anemia, this marker will not be reliable. Second, it is an average, so even if A1c looks optimal, it could be showing the average of very high and very low blood sugar. This is why it is important to have all three markers measured, so you can review the true full picture of blood sugar. 

Vitamin D

Vitamin D is crucial for health since it is responsible for hormone synthesis, modulating inflammation, calcium balance, and more. Because of our largely indoor lifestyles and heavy sunscreen use, most people tend to be deficient in vitamin D. However, vitamin D is a goldilocks nutrient, meaning that more isn’t always better. A level above the optimal range of 50-80 ng/mL can cause your body to leech calcium from your bones and deposit it in your arteries. Vitamin D is not found in abundance in foods, so the best way to get vitamin D is through sun exposure.
Pro Tip: Aim for 15-30 minutes of sun exposure (depending on skin tone; darker skin tones need longer in the sun to produce more vitamin D) without sunscreen, then apply sunscreen for skin health if sitting outside for longer.

Hs-CRP

Hs-CRP is a non-specific marker of whole-body inflammation. It is great to stay on top of this number to know if there is inflammation present in your body, since inflammation is at the root of all chronic disease. There is so much you can do to reduce inflammation in the body such as consuming whole foods, reducing intake of refined sugars and grains, reducing alcohol consumption, and more. An optimal Hs-CRP is <0.9 mg/dL.

Thyroid Panel

The thyroid is the master of your metabolism, telling your body when to speed up or slow down. Testing your thyroid can give you clues as to why you may be struggling with fatigue, weight loss resistance, and poor mood. TSH is a measure of how much stimulation your thyroid needs to produce thyroid hormones and should be between 1.8-2.0 mIU/L for optimal function. Any higher indicates that your thyroid is sluggish and needs more stimulation to produce enough thyroid hormone. T4 is the thyroid hormone produced by your thyroid itself and T3 is the more metabolically active thyroid that is produced from converting T4. Ideally these should be between 6-12 ug/dL and 100-180 ng/dL, respectively.

Stay on top of these labs annually to help support you in knowing what is going on inside of your body. -- We actually created this free Lab Guide to support you with knowledge like this! -- Your doctor should be able to run all of these labs for you, though may refuse some of these if they are not covered by insurance. Our dietitians can run all of these, along with additional conventional markers, in our VIP personalized nutrition program to help you stay on top of your health.