Vitamin D is one of the few vitamins that your body can make for itself—all you need to do is lie in the sun! Your body needs Vitamin D to help it absorb calcium, which makes your bones strong. Vitamin D deficiency can cause rickets, a weakening of the bones, teeth and muscles.
What Types of Food Have Vitamin D?
Vitamin D in the World: Boreal Bleaching
Many evolutionary biologists believe that Vitamin D helps to explain why the human species come in a range of attractive colors. Dark-skinned people migrated to latitudes north of 45° about 50,000 years ago. These chilly pioneers may have evolved lighter skins in order to synthesize more Vitamin D with the limited light available. Other scientists think this is nonsense.
Click on the button to see how Vitamin D plays a role in your:
- Immune System
- Digestive System
- Urinary System
- Intergumentary System
The primary source of Vitamin D for most people is sunlight. Our skin contains a specific type of cholesterol which, when exposed to UV light from the sun, is transformed into Vitamin D3. Vitamin D3 is an inactive form of the vitamin, and must be modified by your liver and kidney to become active.
DNA is your body’s instruction manual. Every cell has your entire set of DNA but only needs to read a small part of it to do its job. Vitamin D can influence how the cells in your immune system do their jobs by acting on the DNA within those cells.
One of Vitamin D’s main roles is to maintain normal calcium levels within your body. When your body senses a low level of calcium, it activates Vitamin D. One way active Vitamin D increases calcium levels is by increasing how much calcium gets absorbed from food in your gastrointestinal tract.
Vitamins can be fat-soluble or water-soluble. Vitamin D is fat-soluble, which means it only dissolves in fat. This makes a big difference for how our body absorbs it. Here, we see Vitamin D from our food entering our stomach.
Vitamin D then moves from the stomach into our small intestine. Here, if it were water-soluble, it would move right into our cells, which are full of water. Since it doesn’t dissolve in water, it can’t be absorbed just yet.