July 21, 2025
Medically Reviewed By Elizabeth A. Swick, MS, RDN

Why is Vitamin D an Essential Nutrient?

Most of us are no stranger to the importance of vitamin D. We know it plays a crucial role in many of our body’s system – far beyond just keeping bones strong. Despite that, research shows that almost half of us are vitamin D deficient.¹

The problem is, it’s not an easy one to get from the diet. Sunlight is the best source, but not all of us have frequent access to the right amount of UV light. And while supplements are abundant, it still can be easy to overlook.

But staying up on vitamin D intake is very important. Why? Because vitamin D is an essential nutrient and our body literally cannot function without it. If you’ve been slacking on vitamin D, let’s take a refresher on why vitamin D is so crucial, the critical benefits of vitamin D, and how to find it in food and vitamin D supplements.

Why Your Body Needs Vitamin D

So, what does vitamin D do exactly?

Vitamin D acts as a hormone, regulating many processes in our body. It’s most well-known for maintaining calcium balance and supporting our bones, but there’s actually so much more.

Studies have shown that other benefits of vitamin D include enhancing the immune system, reducing inflammation, and may even help in chronic conditions such as heart disease, autoimmune disease, and possibly even certain cancers.^2,3

A vitamin D deficiency can lead to symptoms such as fatigue, muscle weakness, bone pain, and even mood disorders such as depression and anxiety.⁴Severe cases of vitamin D deficiency lead to soft, weak bones, a condition called osteomalacia.

Given how much our body depends on vitamin D, it’s not a nutrient to sleep on!

Vitamin D’s Role in Bone Health

One of the most well-established vitamin D benefits is its vital role in maintaining strong bones. Vitamin D helps direct key minerals, especially calcium, into the bone. Without it, our bones would slowly weaken over time.⁵

And weak bones lead to higher risk for fractures and conditions like osteoporosis, which then progressively leads to less movement, weaker muscles and reduced quality of life.

This is why so many health professionals recommend vitamin D supplements as part of an overall bone-health strategy. Because when it comes to our bones, prevention is key.

Always talk with your doctor first before starting any new supplement, but Body Kitchen’s vitamin D + K2 provides a great solution for proper bone health. Offering 5,000IU of highly absorbable vitamin D in every capsule, just take one a day and you are set.

How Vitamin D Helps Absorb Calcium

We know that vitamin D and calcium work together for bone health, but maybe you are still wondering, what does vitamin D do when it comes to calcium absorption?

Think of vitamin D like a gatekeeper. First, vitamin D helps the calcium from food and supplements move from your digestive tract into the bloodstream. Like a gate agent, it seems to regulate how much calcium can pass through at a time.⁵

Once through the gate, calcium now needs further instructions on where to go. Both vitamin D and K2 now help direct it where it’s needed, whether it’s to the bones or teeth. And most importantly, it helps prevent calcium from going where it shouldn’t be, mainly the arteries and other soft tissue.

This powerful nutrient partnership is why now some of the best vitamin D supplements include K2 for better effectiveness. Again, Body Kitchen’s Vitamin D3 + K2 stands as a smart choice if you are looking for a high-quality, comprehensive option.

Vitamin D and a Strong Immune System

Besides bones, vitamin D benefits the immune system as well. Research shows that vitamin D plays a critical role in coordinating our immune response and helping to reduce the risk of infections, especially respiratory infections.⁶

In fact, low levels of vitamin D have been linked to increased risk for colds and flu.⁷ Interestingly, vitamin D levels tend to decrease during the winter when there’s very low sunlight, so keeping up with a vitamin D supplement can be a way to reduce illness and support year-round immune health.

Top Vitamin D Sources to Know

There are 3 main ways our bodies get vitamin D: From sun, food and supplements.

Sunlight
When your skin is exposed to UV light, it makes vitamin D. The amount our body makes can be affected by sunscreen use, pigment of the skin (darker skins absorb less light), and time of year.
Vitamin D Foods
There’s actually only a handful of vitamin D foods, so getting enough from diet alone can be quite tricky. Here are some of the top foods rich in vitamin D:⁸
- Fatty fish (salmon, mackerel, sardines, anchovies, tuna, trout)
- Cod liver oil
- Egg yolks
- Dairy products
- UV-exposed mushrooms
- Fortified foods (non-dairy milks, orange juice, cereals)
Vitamin D Supplements

For many people, a vitamin D supplement is the most reliable way to maintain optimal D3 levels daily. While some supplements offer the D2 form, using a supplement with D3 is typically preferred as this is the form that is active and raises blood levels of vitamin D faster.

Body Kitchen’s Vitamin D3 + K2 fits this criteria, offering a highly absorbable form of D3 with the addition of K2 to increase effectiveness for bone health.

Final Thoughts

So,is vitamin D an essential nutrient? Absolutely, because it plays critical roles in bone health, proper calcium absorption, immune function, and even mood and chronic disease prevention. Essentially, we can’t live without it.

And yet, many of us are not getting enough – especially during the winter months.

The good news is there are several easy, proactive steps you can take, including adding vitamin D foods and using vitamin D supplements, to get your levels up. It’s probably one of the best things you can do for your long-term health.

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