As the days get shorter and sunlight becomes scarce, our natural vitamin D production starts to dip; and with it, so can our energy, immunity, and mood. Known as the “sunshine vitamin,” vitamin D plays a powerful role in everything from hormone balance and immune support to mental well-being. Most people don’t realize how quickly their levels can fall once daylight hours fade.
Why Checking Your Levels Matters
Before reaching for a supplement, it’s important to know where your vitamin D levels actually stand. A simple blood test (25-hydroxy vitamin D) can tell you if you’re deficient or just on the lower side. Everyone’s needs are different depending on factors like where you live, your skin tone, how much time you spend outdoors, and even your gut health. Getting labs done allows you to supplement smartly rather than guessing.
Functional and holistic practitioners often aim for levels between 50 to 80 ng/mL, though some conventional lab ranges may appear lower. If your results come back low, your provider can guide you on an appropriate plan.
The Right Dose and Why It’s Personal
There’s no one-size-fits-all dose for vitamin D. For general maintenance, many adults do well with 1,000 to 2,000 IU daily, while those who are deficient might need 5,000 IU or more under professional supervision. It’s also ideal to take it with a meal containing healthy fats since vitamin D is fat-soluble and absorbs best this way.
If your supplement doesn’t already include vitamin K2, consider adding it. Vitamin K2 helps direct calcium into the bones rather than the arteries, working together with vitamin D for optimal bone and cardiovascular health.
We absolutely love the THORNE - Vitamin D + K2 Liquid with a Metered Dispenser it’s high quality, easy to take, and delivers both nutrients in one convenient drop. This formula is highly absorbable and trusted by health professionals for its purity and effectiveness.
Mood, Sunlight, and Seasonal Depression
If you tend to feel more sluggish, low-energy, or down during the colder months, you’re not alone. Low vitamin D levels have been linked to Seasonal Affective Disorder (SAD), a type of depression that tends to appear when sunlight exposure decreases. Adequate vitamin D can support serotonin production and overall mood balance, acting like a subtle lift for the darker months ahead.
Pairing vitamin D with other sunlight-mimicking habits such as getting outside during morning light, using a light therapy lamp, and maintaining a nutrient-dense diet can make a noticeable difference in how you feel all season long.
The Bottom Line
Think of vitamin D as one of your body’s winter essentials. Getting your labs checked, personalizing your dose, and staying consistent through the colder months can support your immunity, energy, and emotional balance. With the right foundation, you can feel your best and truly thrive through the season instead of just getting through it.
