What are the best food sources of vitamin D, the sunshine vitamin?
Vitamin D is a very unique nutrient: it's essential for many body systems (immune, skeletal, cardiovascular) but unfortunately not found in many foods. During the summer months, when we are able to get outside for 30 to 60 minutes each day, our skin is able to produce adequate vitamin D from daily sun exposure. But during the long, cold, dark winter in the Pacific Northwest, it is wise to pay attention to this essential nutrient.
The most reliable food sources of vitamin D are wild Alaskan salmon, dairy products, eggs and fortified foods such as orange juice and soy milk. Vitamin D is found in smaller amounts in only a handful of other foods, such as mushrooms and pork; seafood and dairy products are definitely the best sources. (See table below for examples of foods providing significant dietary vitamin D.)
- Seafood contains more vitamin D than any other food group. Wild Alaskan salmon is an exceptional source, providing five times the amount of vitamin D as farmed (Atlantic) salmon, making it the best choice for both nutrition and sustainability.
- Dairy products — When milk is "skimmed" of its fat to produce lower-fat milks, the vitamin D also is removed because vitamin D is a fat-soluble nutrient. Luckily, low-fat (and skim) milks are required to be fortified with vitamin D to ensure that we don't lose this precious nutrient in lower-fat milks. Cheeses and other dairy products such as ice cream and yogurt are not required by law to be fortified with vitamin D, so only fluid milk and products made from whole milk will contain this nutrient.
- Eggs also contain vitamin D but only in their yolks, so I advise eating the whole egg to get the whole nutritional package. Pasture-raised chickens spend more time outdoors than any other eggs on the market, and this outdoor sun exposure boosts the vitamin D content of their eggs, making pasture-raised eggs the best choice for both nutrition and sustainability.
- Mushrooms contain a very small amount of vitamin D but you can actually boost the vitamin D in your mushrooms by exposing them to UV light — mushrooms are unique in their ability to produce vitamin D from UV light exposure, just like humans. This only works in the summer months: Simply place your shrooms on a baking sheet and place them in the sunlight for an hour before cooking (think mushroom tanning salon!). If you slice the mushrooms first, this will increase their surface area, and each slice will therefore get more UV exposure and will translate into more vitamin D in your food.
- Fortified foods such as orange juice, soy milk and breakfast cereals often contain vitamin D.
Another convenient way to ensure that you (and your child) are meeting your daily vitamin D requirement during the winter months is to consider a supplement. Tablets, softgels, and multivitamins are available, but the most economical way to supplement with vitamin D is with a liquid supplement. Just place a drop or two of this tasteless, odorless, colorless liquid into your scrambled eggs, on top of your pizza, or into a smoothie and no one will even know they are getting a boost of the sunshine vitamin!
How much do you need?
Infants need at least 400 IUs of vitamin D each day (up to 1000 IUs is considered safe), while older children and adults require 600 IUs/per day. Health professionals often recommend higher intakes for adults (1000 to 2000 IUs) to boost vitamin D levels especially during winter. The vitamin D content of foods and supplements are measured in International Units (IUs), and 1 mg of vitamin D = 40 IUs.
I always advocate getting nutrients from whole food sources, rather than relying on supplements, because whole foods provide additional benefits not found in supplements. But honestly, most of us in the NW need to take a vitamin D supplement during the winter months (October through March). As the table below highlights, if you do not eat salmon or dairy products on a regular basis, it can be very difficult to meet this requirement from foods alone.
|Food||Serving size||Vitamin D (in IUs)|
*Pasture-raised chickens spend more time outdoors than any other eggs on the market and this outdoor sun exposure boosts the vitamin D content of their eggs. This table shows the vitamin D content of conventional eggs.
|Wild Alaskan Salmon||3 oz||500|
|Sardines (canned)||3 oz||230|
|Milk (fortified with Vit D)||1 cup||100|
|Fortified Soy milk / Orange juice||1 cup||100|
Why do we need vitamin D?
Vitamin D is considered a "vitamin" but actually functions more like a hormone in our bodies, regulating many different body systems. Vitamin D helps regulate calcium levels in our blood and helps regulate our immune system, blood pressure and even our secretion of insulin, a hormone that tightly controls our blood sugar levels. A vitamin D deficiency increases the risk for osteoporosis, auto-immune diseases including type 1 diabetes, muscle weakness/pain, and even colds and flus.
Tips to boost your vitamin D intake:
- Make your own vitamin D by getting outside every day between April and October. Our bodies can store vitamin D in our fat tissues and we can draw on these reserves in the winter months.
- Ask your doctor to test your blood vitamin D levels if you are concerned about a possible deficiency.
- If you don't consume seafood or dairy, you should consider keeping a supplement on hand, especially during the winter months. Liquid vitamin D drops are available in doses ranging from 400 to 2000 IUs per drop, and can be conveniently added to foods.
- The Tolerable Upper Intake Level (the maximum amount of vitamin D that is known to be safe to take each day) is 4000 IU for adults and 3000 IU for children aged 4 to 8.