Vitamin D is an essential nutrient for your immune system, heart health, and more. However, most Americans don't get enough vitamin D.

Vitamin-D fortified milk, milk alternatives, and orange juice are great sources of vitamin D. Some waters and sports drinks have added vitamin D as well.

Here’s what vitamin D3 is and why your body needs it.

Vitamin D supplements are widely used around the world, but health experts say it’s important to understand how daily intake can affect the body over time.

Vitamin D deficiency has become increasingly common despite abundant sunlight in many regions. Doctors link the trend to indoor lifestyles, pollution, limited sun exposure, and dietary gaps. Low ...

Many foods—especially fatty fish, UV-exposed mushrooms, and fortified drinks—have significantly higher amounts of vitamin D than milk. Animal-based sources such as cod liver oil, salmon, trout, and ...

Taking vitamin C and D together boosts your immune system and supports bone health. Both vitamins may enhance wound healing and prevent infections.

Vitamin D works with calcium to keep bones strong and healthy. It’s also involved in immune and brain function. Only a few ...

Researchers are still trying to understand why some people develop Long COVID: lasting symptoms of the disease that can ...

In a large, randomized trial, researchers at Mass General Brigham found that high-dose vitamin D3 did not reduce COVID-19 ...

Your skin tone may affect how much vitamin D you have in your blood. But taking vitamin D supplements does not change skin tone. Learn how vitamin D is linked to skin tone and skin health.