This blog is part of our Know Your Vitamins series, where we explore essential vitamins and minerals and how they support overall wellness. Find more educational articles for new supplement starters in our Earthly Insights blog.
Feeling cloudy? Vitamin D might be the missing piece between you and sunnier wellness.
But here’s the thing—despite its sunny nickname, a huge chunk of the population isn't getting enough of it. Whether you’re working a 9-to-5 desk job, living in a northern climate, or just really diligent about your sunscreen game (good for you!), your levels might be lower than you think.
Let’s dive into what this nutrient actually does, where to find it, and how to make sure you’re fueled up for whatever life throws your way.
What is vitamin D?
Vitamin D is a fat-soluble powerhouse that plays a massive role in several critical systems.
Here is the highlight reel of the benefits of Vitamin D:
- Bone & Teeth Health Support: D is best friends with calcium. It promotes calcium absorption in the gut. Without it, your bones won’t have everything they need.¹
- Immune Support: This is a big one. Your immune system is made up of various cells (like T cells and B cells) that actually have Vitamin D receptors. Research shows that Vitamin D helps support both your innate immunity (your first line of defense) and adaptive immunity.²
Basically, it’s working hard behind the scenes to keep your engine running smoothly.
Why is vitamin D called ‘the sunshine vitamin?’
This is the cool part. Unlike other nutrients that you strictly have to eat, your body can actually make Vitamin D when it’s exposed to the sun. (Look at our logo—no wonder we’re fans.)
When your skin is exposed to ultraviolet B (UVB) rays from the sun, it converts cholesterol in your skin into Vitamin D. However, it’s not always that easy. Several factors can block this natural production:
- Sunscreen: While essential for preventing skin aging and cancer, sunscreen blocks the UVB rays needed to make Vitamin D.¹
- Glass: Glass blocks UVB rays. You won’t make any vitamins driving in your car or working by a window.¹
- Latitude and season: If you live north of a certain latitude (think major parts of North America), the sun isn’t strong enough for about six months of the year.¹
- Skin pigment: Higher amounts of melanin in darker skin can reduce the skin's ability to produce Vitamin D from sunlight.¹
Because relying on the weather is a bit of a gamble, getting Vitamin D from other sources is usually necessary.
What foods contain Vitamin D?
If you aren’t catching enough rays, you have to eat your way to optimal levels. The catch? Very few foods naturally contain significant amounts of Vitamin D. The recommended daily amount is about 20 mcg for adults (400 IU).
Here are the heavy hitters if you are looking to boost your intake through diet:³
- Fatty fish: This is the gold standard. Salmon, trout, mackerel, and tuna are decent sources. For example, 3 ounces of cooked salmon gives you about 14 mcg (570 IU).
- Yogurt and kefir: While significantly less than fatty fish, 1 cup of these dairy staples can provide about 2-3 mcg (100 IU) of vitamin D.
- Mushrooms: They are one of the only plant sources that naturally contain the vitamin.
If you’re doing math, that’s about eight cups of yogurt or kefir to reach your RDI. That’s why smart supplementation is so essential in making up the difference.
What are the best Vitamin D supplements?
Because it’s tough to eat enough salmon every single day, and winter happens to the best of us, supplements are a fantastic way to fill the gap.
But not all bottles on the shelf are created equal. Here is what you should look for to ensure you’re getting a quality product:
- Transparency: If it’s going in your body, there should be no question about the contents. Look for brands that are open about their sourcing.
- Testing: This is non-negotiable. You want a brand that tests raw materials and the finished product. Look for GMP-certified facilities and ISO-accredited labs.
- Potency: The RDA (Recommended Dietary Allowance) is around 20 mcg for adults, and not all vitamin D supplements reach those levels.
At the end of the day, the best supplement is one you actually take. Consistency is key!
Sun-to-soil supplements for immunity and bone health
We believe in making supplements we’d take ourselves (and we have some pretty high standards). Whether you prefer plant-based options or the active D-3 form, we’ve got you covered with products that are triple-tested for purity and potency.
- Strengthening D-2 50 mcg: Our D-2 is sourced from sun-exposed fungi and supports immunity and bone health.*
- Strengthening D-3 50 mcg: Sourced from Cholecalciferol, the most active form, this fat-soluble softgel also supports immune function and bone health.*
Fueling your best life
Vitamin D plays a massive role in how you feel, your bone strength, and how your immune system fortifies you when you need it.*
Here’s to staying sunny, even when the weather isn’t.
*These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.
Resources
- Laird E et al. Vitamin D and bone health: potential mechanisms. Nutrients, July 2010. https://pmc.ncbi.nlm.nih.gov/articles/PMC3257679/.
- Aranow C. Vitamin D and the immune system. J Investig Med. 2011;59(6):881-886. https://pmc.ncbi.nlm.nih.gov/articles/PMC3257679/.
- Food sources of vitamin D. Dietary Guidelines for Americans, 2025. https://www.dietaryguidelines.gov/resources/2020-2025-dietary-guidelines-online-materials/food-sources-select-nutrients/food-sources-vitamin-d.