Vitamin D is an essential vitamin that many people do not get enough of. Although your body can produce its own vitamin D using cholesterol in your skin chances are you’re not exposed to enough sunlight to properly make all the vitamin D that your body needs.
But what exactly is vitamin D and why is it so important? Can you get enough vitamin D through your diet alone or do you need to take a supplement? The following article will answer all of your vitamin D questions so you can ensure you’re getting the right amount of this vital nutrient.
Types of vitamin D
There are two main sources of vitamin D, ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). Both help your body build bone by increasing your ability to absorb phosphate and calcium but the difference lies in how they do that. (1)
Vitamin D2 is sourced from plants and it’s typically the type of vitamin D that’s added to fortified foods. On the other hand, Vitamin D3 is sourced from animals and it’s the type that your body produces naturally. (2)
According to the American Journal of Clinical Nutrition, vitamin D3 supplements may be more effective than their plant-sourced counterparts when it comes to raising the levels of vitamin D in your blood. This is because your own body produces vitamin D3 (3)
What does vitamin D do for you?
Vitamin D is essential for keeping your bones, teeth and muscles healthy and strong. It does this by regulating the amount of calcium and phosphate your body produces. The most common source of vitamin D is sunlight. (8)
Your race, age and sunscreen use all play a role in how much vitamin D is absorbed through your skin. In addition, where you live also plays a major role since the intensity of the sun’s rays change based on your latitude, the pollution in the air and the time of year.
When your skin is exposed to sunlight it produces a chemical (7-dehydrocholesterol) which absorbs the UV-B rays. Once absorbed, your body converts the UV-B rays into pre-vitamin D which in turn is metabolized by your liver and kidneys and turned into a usable form of vitamin D. Most of the cells in your body have a vitamin D receptor which means that this vitamin is important all-throughout your body. (9)
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Foods containing vitamin D
When searching for foods that contain vitamin D, your pickings are unfortunately slim. This doesn’t mean that it’s impossible to get your RDI (recommended daily intake) of vitamin D from your diet. In fact, by incorporating some of the following foods into your meals you’ll provide your body with a lot of the vitamin D it requires. (4)
- Cod liver oil– a single teaspoon of cod liver oil contains 450IU which is 75% of your RDI of vitamin D
- Mushrooms-certain mushrooms such as dried shiitake (154 IU per 100g) and raw maitake mushrooms (1124 IU per 100g) contain vitamin D naturally.
You can also get mushrooms that are grown under UV light. The UV light is absorbed by the mushrooms and passes the vitamin D on to you when it’s eaten. Raw Portobello (1136 IU) and raw white mushrooms (1046 IU per 100g) are two of the species that can be grown under UV light.
- Egg yolks-when you eat free-range eggs the yolk in the eggs will be higher in vitamin D because the hens were allowed to forage. A serving of 2 whole eggs contains 88 IU of vitamin D which is roughly 15% of the DRI. (In search of a great egg recipe? Click here!)
- Fatty fish-fish such as swordfish and herring are great sources of vitamin D. Swordfish provides you with a whopping 117% of your body’s RDI of vitamin D (706 IU) per serving while a fillet of herring offers 306 IU which is roughly half your RDI of vitamin D.
Fortified sources of vitamin D
Several common foods are fortified by vitamin D; because, it only occurs naturally in a few foods. It’s better to get your vitamin D from natural sources whenever you can since they’re lower in sugar and preservatives. If you’re not a big fan of fish or you’re still struggling to get enough dietary vitamin D, the following foods are often fortified with this essential vitamin (7)
- Milk- a single cup can contain between 115 and 124 IU of vitamin D
- Orange juice- a cup of fortified orange juice can contain 137 IU f vitamin D
- Yogurt- if your yogurt has been fortified with 20% of your DRI of vitamin D then you can expect roughly 80 IU per 6 oz serving
- Cereals-different cereals contain different levels of vitamin D but in a single cup serving of cereal that’s been fortified with 10% of your DRI of vitamin D you can expect roughly 40IU of the vitamin
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Healthy doses of vitamin D
How much vitamin D should you be consuming a day? The Institute of Medicine (IOM) in the United States reviewed numerous studies on the amount of vitamin D you truly need to be healthy. In 2011 a report came out that summarized their findings. This report led to a change in the recommended daily allowance of vitamin D. If you’re 70 or younger you should be getting 600 IU of this essential vitamin daily. However, if you’re over 70 then this goes up slightly to 700 IU a day. (5)
Can you have too much vitamin D?
Vitamin D has been controversial in recent years with many people claiming through anecdotal evidence that extremely high levels of vitamin D offer a host of health benefits that extend beyond helping your body absorb calcium. This leads to the question, can you have too much vitamin D?
According to the same scientists who reviewed the numerous studies referenced above, the answer is yes. Too much of a good thing can be a bad thing. For most people, the safe upper intake of vitamin D falls between 2000 and 4000 IU.
If you take more than 4000 IU of vitamin D a day then you put your body at risk of building up too much calcium in the body. This can lead to a potentially life-threatening condition known as hypercalcemia. Also, an excess of calcium can also increase your risk of developing kidney stones. (6)
Vitamin D is essential for the maintenance of strong bones, teeth and healthy muscles. You can get a lot of your vitamin D through sunlight through the warmer months. A diet that’s rich in vitamin D includes fatty fish, mushrooms and free-range eggs. Be cautious about taking too many vitamin D supplements and always seek the advice of a medical professional before making any major dietary or supplemental changes.
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Kaitlyn Bain is a professional health and wellness writer with a passion for helping her clients educate their readers on healthy lifestyles.