Vitamin D is one of the four fat-soluble vitamins (see blog on Vitamin & Mineral Skittles) that we get through the diet.1 However, it is unique to other vitamins in that it is also a hormone that our bodies produce.1 It has many crucial functions in the body like making sure our phosphorus and calcium are balanced between our bones and being available in the bloodstream, reducing cancer cell growth, infection control, and in reducing inflammation.1 There are many other speculated roles of vitamin D due to presence of vitamin D receptors in many of the body’s organs and tissues.1 Some studies have found that those with adequate vitamin D levels tend to have better bone health, lower risk for cardiovascular and other heart diseases/conditions, reduced rates of type II diabetes, and decreased risk of developing multiple sclerosis.1 

 

There are two forms of this vitamin, D2 which is found in plants and fungi, and D3 which is found in animals.1 Vitamin D can be tricky to get through the diet as very few foods naturally contain it.1 The neat thing, however, is that the body is actually able to synthesize (make) it from the sun using our skin.1 During cold winter months or in areas with limited sunshine exposure, it can be a bit more difficult to get an adequate amount of time in the sun to make enough of this vitamin for important body functions.1 In addition, those individuals with darker colored skin may need additional sun exposure or vitamin D in the diet since their pigmentation mimics being covered by the shade.1 One way to think about this would be to compare it to someone who is cooking a dish. If you cooked it at a lower temperature it would need to cook longer to get the same finish as someone who cooked it at a higher temperature for less time (or in this case to make vitamin D).

 

Sun exposure is by far the easiest way to get adequate vitamin D levels.1 Researchers say it only takes about 30 minutes per day to reach recommended levels this way, however, when this is not possible there are alternatives to consider.1 

Since there are not many foods that naturally contain vitamin D, many products have been fortified (simply meaning vitamin D is added to a food that would not typically have it). These would include dairy and plant milk products, orange juice, and cereals.1 It is important to keep in mind that not all fortified foods are nutrient dense (meaning they won’t contribute much value to your diet or health) and many have added sugars or sodium.2  When trying to find vitamin D fortified foods, look for the word fortified or enriched on the package and check the nutrition label (see blog on How to become a Pro at Reading a Nutrition Label) to avoid added sugars or sodium. Some good options to look for include unsweetened almond milk, unsweetened soy beverages, non-fat or low-fat dairy milk, yogurt, or 100% orange juice.2 Just make sure to keep in mind it is always best to get your nutrients from whole foods rather than processed foods whenever you can.

 

The foods that do naturally have good sources of vitamin D include fatty fish like cod liver oil, sardines, salmon, swordfish, tuna, beef liver, mushrooms, and egg yolk.1 Taking a vitamin D supplement is recommended for those who do not get adequate sun exposure or who are not able to consume vitamin D rich foods.1 It is recommended that individuals get 600 IU daily for men and women and 800 IU for those over the age of 70.1 Here are some way to get vitamin D into your diet:

  • 3 oz. Salmon = 383-570 IU
  • 3 oz. Light Tuna, Canned = 231 IU
  • 3 oz. Tilapia = 127 IU
  • 1 cup Unsweetened, Fortified Dairy or Dairy Alternative = 115-120 IU
  • 1 cup Mushrooms, raw = 114-1110 IU

(important note: mushrooms have a huge range of IU depending on which mushrooms you choose. Those grown in natural UV sunlight are higher than those grown indoors. An easy way to make sure you are getting sun exposed mushrooms is to shop at a local farmers market or natural foods store).2

Being vegan or vegetarian, having darker pigmentation, living in areas with limited sunlight, and limiting sun exposure with excessive sunscreen or wearing several layers of clothing are all risk factors for inhibiting vitamin D status that we should keep in mind.1 Talk to your physician if you are thinking about taking a supplement to see if this is the best option for you.1 Just remember, food first is always best (or for vitamin D getting some sunshine too) so it is always recommended to incorporate healthy whole foods with vitamin D whenever possible. And next time you find yourself bathing in the sun, don’t forget you are working hard on making one of the coolest vitamins in our body, vitamin D.

 

References

  1. Office of dietary supplements – vitamin D. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/. Accessed January 21, 2022.
  2.  Resources. Food Sources of Vitamin D | Dietary Guidelines for Americans. https://www.dietaryguidelines.gov/resources/2020-2025-dietary-guidelines-online-materials/food-sources-select-nutrients/food-sources. Accessed January 25, 2022.

 

Post created by Your Life Nutrition student intern from the University of Akron: Michaela Campbell