Vitamin D or sun shine vitamin is actually not a vitamin at all, it’s a hormone created in our body when we’re exposed to sun light for at least 20 minutes every day. But it also can be taken with food. Vitamin D foods are mostly animal products. Animal based vitamin is called D3 and it’s found in fatty fish, oysters, fatty pork meat, eggs, milk and beef liver. Plant based foods have D2 vitamin and most of it have mushrooms, especially shiitake. White mushrooms have less vitamin D than shiitake. D3 vitamin is 3 times more potent than D2. Vitamin D created in the body when exposed to sun is D3.
Among fatty fish, significant amounts of vitamin D can be found in salmon, tuna, herring, trout, sardines and mackerel.
Some white fish also have significant amounts of vitamin D, especially flounder and sole.
Similarly to vitamin A, vitamin D is also fat soluble, and that means that you have to eat it with fat to absorb it.
Vitamin D is required for absorbing calcium and repairing bone, cell growth and immune system. It also prevents inflammation. If you don’t get enough of vitamin D, you’re risking weakened immune system, weakened hair grow, weakened bones and muscles. And you’d be also increasing risk of getting cancer, especially colorectal and pancreatic. Lack of vitamin D is also linked to obesity, diabetes, hypertension, heart attack and stroke.
Luckily, extra amounts of vitamin D can be stored in the body.
Vitamin D is measured in international units and daily requirement is 600 UI/day. Fatty fish provides between 270% of daily requirement (herring), 120% (canned Salmon) and 40% (oil packed tuna) per 100 gram serving. One tablespoon of cod liver oil has whooping 340% of daily requirement. Higher amounts of vitamin D (1000-2000 UI per day) are critical for disease prevention, especially cardiovascular disease. Research shows that people with low vitamin D levels are at double risk of getting heart attack or stroke. There are evidences that vitamin D also fights cognitive decline, arthritis, depression and type 2 diabetes.
Most Americans are not enough exposed to sun in winter months and vitamin d rich foods are not really very often consumed. Center for Disease Control and Prevention found out that more than 50% of Americans are vitamin D deficient. Luckily, vitamin D is available as a supplement.