Snowy skies and cozy nights might feel festive, but winter can be hard on your body behind the scenes. Your mood, your immune system, even your heart can all take a hit.
“In winter months, you don’t get as much sunlight, which impacts mood. The busy holiday season can also cause stress. When you’re stressed or sad, it can increase inflammation and spike blood sugar. It’s a cascade of effects,” says Lifeforce Clinician Reshma Patel, PA-C. “All of these together are the perfect storm for heart attacks and strokes.” Research shows that cardiovascular disease and cardiac death are more prominent in the winter months.
So, how do you combat these chilling effects? The first step is testing your biomarkers regularly so you know where you stand. Our experts break down the five biomarkers most impacted in the winter — plus how you can optimize them to stay happy and healthy this season.
1. Vitamin D
What it is: Nicknamed the sunshine vitamin, vitamin D is actually a hormone. It’s made from cholesterol in your skin when it’s exposed to the sun. Testing for 25-Hydroxy (25-OH), a form of vitamin D produced in the liver, is the most common way to measure how much D is in the body.
Optimal levels: 50 - 100 ng/mL
Why it’s impacted by winter: “Shorter days and less sunlight mean reduced UVB exposure. Your skin simply can’t synthesize enough vitamin D,” says Lifeforce Clinician Melanie Jones, FNP-C. A dip in D can be concerning because it impacts multiple systems in the body. “You need vitamin D to make hormones, protect bones, and keep your immune system strong,” says Patel. “With lower levels, you can be more susceptible to viruses like COVID, flu, and RSV.”
How to optimize it: Patel notes that it’s challenging to get ample vitamin D through food — sun and supplementation are the most effective ways to raise your levels. “Though it’s colder, try to go outside and get some sunlight, even just to your face,” Patel suggests. “Sitting next to a window can even help.”
Both experts recommend supplementing with Vitamin D+K. “I encourage doubling up on our D+K during winter, especially in colder climates with very short days and blistery winters,” Jones says. Talk to your clinician about the right dose for you.
2. High-Sensitivity C-Reactive Protein (hsCRP)
What it is: This is a marker of inflammation in the arteries, which can spike due to viral or bacterial infections or more prolonged factors like smoking, autoimmune disorders, and lifestyle habits. Research shows that high levels of hsCRP can increase the risk of future heart attack.
Optimal levels: Less than 1 mg/L
Why it’s impacted by winter: A study in PLOS One found that hsCRP levels tend to be higher in November through April than May through October. “Winter brings more viral infections, inflammation, and less physical activity, which can all drive up hsCRP,” Jones says. Patel also points to less active lifestyles in colder months. “When you’re more sedentary, blood gets stagnant, which can increase hsCRP,” she warns.
How to optimize it: “Any kind of movement you can do — whether it’s working out indoors or simple walking — will help because it increases circulation,” Patel says. “If you’re sitting at a desk all day, try doing heel lifts or calf raises. They increase blood flow to the calves, one of the largest muscles in the lower body. You can also do sets of squats between meetings. The key is getting little ‘exercise snacks’ throughout the day.”
Jones suggests eating anti-inflammatory foods such as colorful fruits and veggies and healthy fats with omega-3 fatty acids. “Prioritizing sleep and stress management can also help lower baseline inflammation,” she says. Plus, studies show that saunas are linked to reducing hsCRP.
3. LDL Cholesterol
What it is: LDL, which stands for low-density lipoprotein, is often dubbed the “bad cholesterol” because when it’s circulating in higher amounts in your bloodstream, it increases your cardiovascular risk.
Optimal levels: Less than 90 mg/dL
Why it’s impacted by winter: Research shows that both LDL and total cholesterol rise in the chillier months. According to Jones, the culprits are often less activity, unhealthy holiday eating, and possibly cold exposure triggering changes in how the body metabolizes lipids. Patel also notes that in some parts of the country it’s more challenging to find fresh, colorful, nutrient-packed produce in the winter, which can lead to choosing more processed foods.
How to optimize it: Don’t skimp on fiber, which has been shown to lower LDL. Jones recommends opting for oats, chia seeds, and plenty of vegetables. If you don’t have easy access to fresh produce, Patel suggests organic frozen options. “Frozen fruits are great in smoothies,” she says. “Frozen vegetables are best cooked and whole, rather than in a juice or smoothie, because whole veggies retain their fiber content and help decrease cholesterol.” For a cozy winter meal, cook up a stew or soup with sweet potatoes, butternut squash, and as many green veggies as you can.
According to Jones, taking a brisk walk after meals can help maintain lipid balance, and strength training can improve the ability of HDL (aka the “good cholesterol”) to remove cholesterol from cells. She also recommends Peak Healthspan™ and LF Omega to support heart health.
4. Red and White Blood Cells
What they are: Red blood cells are responsible for carrying oxygen from your lungs to every cell in your body, helping your cells grow, produce, and stay optimized. White blood cells are your body’s defenders, which mobilize to fight off infections.
Optimal levels:
Red blood cells (RBC): 3.8 - 5.3 x10E6/uL
White blood cells (WBC): 3.4 - 10.8 x10E3/uL
Why they’re impacted by winter: “The immune system is under greater demand in winter, and white blood cells may temporarily rise with infections,” Jones says. “Some studies show red blood cells and hemoglobin can also vary slightly with dehydration or less oxygen exposure from staying indoors.” Patel also notes that blood vessels constrict in colder weather, which makes it harder for blood to flow and can increase white and red blood cells and blood pressure.
How to optimize them: “Keep your body warm with regular movement, hot yoga, an infrared sauna, or even just turning up your thermostat,” Patel says. “That will help increase blood flow.”
Optimal hydration also ensures that red blood cells deliver oxygen efficiently throughout the body and white blood cells are able to travel so they can fight infections. Jones also advises to maintain adequate iron and B vitamin intake and to talk to your clinician about LF Methylation, which regulates levels of homocysteine, an amino acid that supports blood cells.
5. Hemoglobin A1C
What it is: When glucose levels are elevated, some of it attaches to hemoglobin, a protein found in red blood cells. Hemoglobin A1C is the percentage of hemoglobin floating in your blood that has sugar stuck to it. This marker is often used to diagnose diabetes.
Optimal levels: Less than 5.3%
Why it’s impacted by winter: “Less activity, heavier comfort foods, and holiday indulgences can all raise your glucose levels,” Jones explains. “Less sunlight may also reduce insulin sensitivity through lower vitamin D and serotonin levels.”
Stress can also be a major Scrooge this season. “The holidays can be a stressful time for many, and when cortisol levels spike, it can lead directly to increased blood sugars,” Patel says. “High cortisol and blood sugars can hijack your hormones, affect mood, and cause weight gain.”
How to optimize it: As much as possible, stick with a consistent exercise routine — especially resistance training — and eat balanced meals packed with protein and fiber, Jones suggests.
You should also focus on soothing stress. “You can’t control how much stress comes in. All you can do is mitigate it,” Patel says. “Find one or two stress management techniques that work for you.” Some of Patel’s favorites: soaking in direct sunlight within an hour of waking up, walking barefoot in the grass or sand, standing on a grounding mat, practicing hot yoga, relaxing in an infrared sauna, breathwork, and meditation. “Meditation can be anything from journaling to painting, basketball, ironing, skiing, or snowboarding,” Patel says. “Whatever brings you pleasure, try to do more of that.”
This article was medically reviewed by:
Reshma Patel, PA-C, MMS, Integrative and Functional Medicine Practitioner
Melanie Jones, APRN-C, AANP Board Certified Family Practitioner
