Vitamin D

Vitamin D is a fat-soluble vitamin that is naturally available in many foods. When ultraviolet rays from sunlight hit the skin and trigger vitamin D synthesis, it is produced endogenously. For activation in the body, vitamin D must undergo two hydroxylations.
- The first calcidiol occurs in the liver and converts vitamin D to 25-hydroxyvitamin D [25(OH)D],
- The second calcitriol occurs primarily in the kidney and forms the physiologically active 1,25-dihydroxy vitamin D [1,25(OH)2D].
Strong bones
Vitamin D plays an essential role in the calcium regulation and maintenance of phosphorus levels in the blood. Both are essential for maintaining healthy bones. Vitamin D is needed for the intestines to absorb calcium.
Prevention from dementia and cognitive decline
Vitamin D plays an essential role in cognitive function and significantly decreases the risk of dementia. Vitamin D may help clear up amyloid plaque, attributed to Alzheimer’s disease, which is the most common form of dementia.
Protection against respiratory infection
Adequate vitamin D protects from respiratory infections such as the common cold and flu. Recommended levels have been shown to decrease the risk of upper respiratory tract infections and tuberculosis.
Prevent type 2 Diabetes
Vitamin D plays an essential role in helping increase insulin sensitivity, boost beta-cell function, reduce inflammation; all these are beneficial for reducing the risk of and helping manage type 2 diabetes
Recommended daily amount for Vitamin D
The recommended daily allowance of vitamin D is 600 international units (IU) for most people ages 1 to 70. For people over the age of 70, it is 800 IU, and it is 400 IU for infants.
Food sources
Vitamin D present in very few foods in nature. The flesh of fatty fish (such as salmon, tuna, and mackerel) and fish liver oils are the best sources. In the beef, liver, cheese, and egg, yolks are found minimal amount. Vitamin D found in these foods is primarily in vitamin D3 and its metabolite 25(OH)D3. Some mushrooms provide vitamin D2 in variable amounts. There are two types of vitamin D supplements. They are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol).
Maple glazed salmon

Ingredients
- 1 tablespoon maple syrup
- 1 tablespoon hoisin sauce
- 1 teaspoon Dijon mustard
- 1/4 teaspoon coarsely ground black pepper
- 2 (6-ounce) salmon fillets (about 1 inch thick)
- Cooking spray
Method
- Preheat broiler.
- Combine the first 4 ingredients in a small bowl, stir with a whisk.
- Place salmon, skin side down, on a broiler pan coated with cooking spray. Brush with maple mixture. Broil 10 to 12 minutes or until fish flakes easily when tested with a fork, brushing with maple mixture after 5 minutes and again after 10 minutes.
Nutrient profile
- Calories per serving 320
- Calories from fat per serving 38%
- Fat per serving 13.6g serving 3.2g
- Protein per serving 36.6g
- Carbohydrate per serving 10.7g
- Fiber per serving 0.3g
- Cholesterol per serving 87mg
- Iron per serving 0.9mg
- Sodium per serving 273mg

References
- Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Calcium and Vitamin D. Washington, DC: National Academy Press, 2010.
- Mattila PH, Pyronin VI, Uusi-Rauva EJ, Koivistoinen PE. Vitamin D contents in edible mushrooms. J Agric Food Chem 1994; 42:2449-53.
- Calvo MS, Whiting SJ, Barton CN. Vitamin D fortification in the United States and Canada: status and data needs. Am J Clin Nutr 2004; 80:1710S-6S. [PubMed abstract]
- Mattila PH, Pyronin VI, Uusi-Rauva EJ, Koivistoinen PE. Vitamin D contents in edible mushrooms. J Agric Food Chem 1994; 42:2449-53.
- https://www.health.com/author/ella-quittner