Why Vitamin D Matters for Kids (and yourself) During Long, Cold Winters
Why Vitamin D Is Critical for Kids During Long Northern Winters
If your winters look like endless snow, cloudy skies, and kids bundled in snowsuits, you’re not alone.
Living in northern climates has many benefits — beautiful winters, outdoor adventures, and cozy family time. But it also means months with very little sunlight, which can make it difficult for our bodies to produce enough vitamin D.
Even on sunny winter days, most of our skin is covered with jackets, gloves, hats, and snow pants. That means very little skin exposure to the sun, limiting the body’s ability to naturally make vitamin D.
For growing children (and adults too), maintaining healthy vitamin D levels during winter is especially important.
Why Vitamin D Is So Important for Kids
Vitamin D is often called the “sunshine vitamin”, but its role in the body goes far beyond sunlight.
For children, vitamin D supports several key systems involved in growth and development.
Vitamin D helps support:
Healthy bone development
Proper calcium absorption
A strong immune system
Normal growth and development
Children experience rapid bone growth throughout infancy, childhood, and adolescence. Vitamin D helps ensure that calcium is properly absorbed and utilized to support strong bones.
Vitamin D is also known to help regulate immune function, which is one reason it becomes a popular topic during cold and flu season.
Why Vitamin D Deficiency Is Common in Winter
Our bodies naturally produce vitamin D when UVB rays from sunlight hit the skin.
However, several factors make vitamin D production difficult during winter months — especially in northern regions.
Common reasons vitamin D levels drop in winter:
Shorter daylight hours
Increased cloud cover
Cold temperatures that require heavy clothing
Lower UVB intensity at northern latitudes
In many northern areas, the sun’s angle during winter months is too low for meaningful vitamin D production, even on bright days.
While certain foods contain vitamin D — such as fatty fish, egg yolks, and fortified dairy — it can be difficult to meet optimal levels through diet alone.
This is why many families consider vitamin D supplementation during the winter months.
Why We Choose Vitamin D3 + K2
When we choose a vitamin D supplement for our family, we look for vitamin D3 paired with vitamin K2.
Vitamin D3 (Cholecalciferol)
Vitamin D3 is the form most easily used by the body and is the same form produced when sunlight hits the skin.
Vitamin K2
Vitamin K2 works alongside vitamin D by helping guide calcium to the bones and teeth, where it belongs.
Together, vitamin D3 and K2 support healthy calcium metabolism, which is why this combination is often recommended in functional wellness circles.
Experts like Mark Hyman and Rhonda Patrick frequently discuss the importance of maintaining healthy vitamin D levels for immune health, bone strength, and overall wellness.
Why We Prefer Liquid Vitamin D Drops
For children especially, we prefer liquid vitamin D drops rather than capsules.
Liquid drops make it easier to:
Adjust dosing for different ages
Mix into food or drinks
Give to younger children who can’t swallow pills
They also allow flexibility if your healthcare provider recommends adjusting dosage.
How to Choose a High-Quality Vitamin D Supplement
Not all supplements are created equal. When selecting a vitamin D supplement for your family, it’s helpful to look for a few key qualities.
Look for supplements that include:
Vitamin D3 (cholecalciferol) rather than D2
Vitamin K2 (MK-7) for balanced calcium metabolism
Third-party testing for purity and potency
Clear dosing instructions appropriate for children
For our family, we prefer professional-grade supplements that are third-party tested and available through practitioner dispensaries.
👉 If you'd like to see the Vitamin D3 + K2 drops we use, you can find them in my Fullscript supplement dispensary here.
Fullscript offers high-quality supplements from trusted brands and at discounted pricing compared to retail stores.
Other Ways to Support Healthy Vitamin D Levels
Supplementation can be helpful during darker months, but it’s only one part of a healthy winter routine.
We also focus on:
Spending time outdoors when sunlight is available
Eating nutrient-dense whole foods (like salmon)
Supporting good sleep habits
Maintaining a balanced diet rich in minerals
These simple habits help support overall wellness during long winter seasons.
Final Thoughts: Supporting Kids Through Winter
For families living in northern climates, winter can bring unique wellness challenges — especially when it comes to sunlight exposure.
Vitamin D plays an important role in bone health, immune function, and overall growth, making it an important nutrient to pay attention to during darker months.
For our family, a vitamin D3 + K2 supplement is one simple step we take to help support healthy levels through the winter season.
If you'd like to explore the supplement we use, you can find it in my Fullscript dispensary here.
This article is for educational purposes only and is not intended as medical advice. Always consult with your pediatrician or healthcare provider before starting supplements for children.
Reference: PMID: 28722941
