As the winter months roll by, daylight hours are scarce and temperatures drop, causing many of us to spend more time indoors. Unfortunately, this also means less exposure to the sun—the body’s primary source of vitamin D.
Dubbed the "sunshine vitamin," vitamin D plays a crucial role in supporting bone health, immune function, and mood regulation. Without adequate sunlight, the risk of vitamin D deficiency increases, leading to fatigue, weakened immunity, and even seasonal affective disorder (SAD).
So, how can you ensure your body gets enough vitamin D during the colder months? While supplements are an option, incorporating vitamin D-rich foods into your diet is a natural and effective way to maintain optimal levels.
Why is Vitamin D Important?
Optimal vitamin D levels help keep our bodies healthy and functioning properly. Most notably, vitamin D works with calcium to support proper bone growth and maintain strength throughout adulthood. Beyond bone health, vitamin D also plays a crucial role in boosting the immune system, helping fight off both acute and chronic illnesses. Additionally, it may reduce the risk of depression.
Simply put, vitamin D is an essential micronutrient!
Adults should try to take in 15 mcg (600 IU) of vitamin D per day, with older adults above 70 ideally aiming for 20 mcg (800 IU) per day. With limited sunlight in the winter, hitting these numbers can be challenging. Fortunately, certain foods can help compensate for reduced sun exposure.
Incorporating the following five vitamin D-rich foods into your winter diet can help maintain healthy levels and support overall well-being.[1]
1. Fatty Fish
Fatty fish, such as salmon, mackerel, and sardines, are among the best natural sources of vitamin D. Wild-caught salmon, in particular, is a standout, providing between 600 and 1000 IU of vitamin D per serving. Farmed salmon contains less, but still offers a significant amount. Mackerel and sardines also contribute to daily vitamin D needs, along with a hearty dose of omega-3 fatty acids, which support heart health and reduce inflammation.
Incorporating fatty fish into your diet is relatively easy. A grilled salmon fillet with roasted vegetables makes for a nourishing meal, while canned sardines can be added to salads or whole-grain toast for a quick and nutritious snack. Mackerel works beautifully in stews or pasta dishes, adding depth of flavor and a nutritional boost.
Eating fatty fish at least twice a week is a simple and effective way to maintain healthy vitamin D levels throughout the winter.[2]
2. Fortified Dairy and Plant-Based Alternatives
For those who consume dairy, fortified milk and yogurt offer an excellent way to boost vitamin D intake. Many commercial brands enrich their products with this vital nutrient to help counteract common deficiencies. A single cup of fortified milk typically contains around 100 IU of vitamin D, making it an accessible and convenient option.
If you follow a plant-based diet or are lactose intolerant, fortified plant-based milks such as soy, almond, and oat milk provide a great alternative. These products are often enriched with vitamin D at similar levels to cow’s milk. Whether poured over cereal, blended into smoothies, or simply enjoyed in a warm beverage on a cold day, fortified dairy and plant-based milks can make a meaningful difference in your winter nutrition.[3]
3. Eggs
Eggs, particularly the yolks, contain a moderate amount of vitamin D, making them a valuable addition to a balanced diet. One egg yolk provides about 40 IU of vitamin D, though eggs from pasture-raised or vitamin D-enriched hens can offer even more.
Eggs are incredibly versatile and easy to include in meals. A simple breakfast of scrambled eggs with spinach and mushrooms provides a nutrient-rich start to the day. Omelets and frittatas loaded with colorful vegetables make for satisfying meals, while hard-boiled eggs serve as a convenient snack packed with protein and essential vitamins.
Choosing eggs from pasture-raised sources or those specifically fortified with extra vitamin D can further enhance your intake.[4]
4. Mushrooms
Unlike most plant-based foods, mushrooms have the ability to produce vitamin D when exposed to sunlight. However, not all mushrooms are rich in this nutrient—only those that have been specifically treated with UV light provide significant amounts. Portobello and maitake mushrooms, for example, can offer between 400 and 600 IU of vitamin D per serving when properly exposed to light.
Adding mushrooms to your diet is both delicious and beneficial. A creamy mushroom soup makes for a comforting winter meal, while sautéed mushrooms can enhance pasta, stir-fries, and grain bowls. Grilled portobello mushrooms also serve as a fantastic meat substitute, bringing both texture and depth of flavor to plant-based dishes.
When shopping, look for mushrooms labeled as "UV-exposed" to ensure you’re getting the most vitamin D possible. If you purchase fresh mushrooms, leaving them in direct sunlight for a few hours before cooking can also increase their vitamin D content naturally.[5]
5. Cod Liver Oil
For those looking for an especially concentrated source of vitamin D, cod liver oil is a time-tested solution. A single teaspoon of cod liver oil can provide between 400 and 1000 IU of vitamin D, making it one of the most potent dietary sources available. In addition to vitamin D, cod liver oil is rich in omega-3 fatty acids and vitamin A, both of which support immune function and overall well-being.
While the strong taste of cod liver oil may not be for everyone, there are flavored versions available that make it more palatable. It can also be taken in capsule form for those who prefer a more convenient option. Some people choose to mix a small amount into smoothies or salad dressings to mask the flavor while still reaping the benefits. Because it contains high levels of vitamin A, it’s important to use cod liver oil in moderation and follow dosage recommendations.[6]
Additional Ways to Maintain Vitamin D Levels in Winter
Beyond diet, there are additional ways to support healthy vitamin D levels during the winter months. When weather permits, spending time outdoors—particularly around midday—can help the body synthesize vitamin D naturally, even when sunlight is limited.
If dietary sources are not sufficient, vitamin D supplements can provide a reliable alternative, especially for individuals at higher risk of deficiency. Regularly checking vitamin D levels through blood tests can also help ensure you’re getting enough of this crucial nutrient.
Final Thoughts
As winter reduces our exposure to natural sunlight, maintaining adequate vitamin D levels becomes essential for overall health. By incorporating fatty fish; fortified dairy or plant-based milk; eggs; mushrooms; and cod liver oil into your diet, you can support your body's vitamin D needs and reduce the risk of deficiency. Making these foods a regular part of your meals will not only help sustain your energy and immunity but also contribute to long-term well-being.
Prioritizing nutrition during the colder months is a simple yet powerful way to stay healthy and resilient. With the right food choices, you can keep your vitamin D levels optimized and thrive throughout the winter season.
References:
1. U.S. Department of Health and Human Services. (n.d.). Office of dietary supplements - vitamin D. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/.
2. Lu Z, Chen TC, Zhang A, Persons KS, Kohn N, Berkowitz R, Martinello S, Holick MF. An evaluation of the vitamin D3 content in fish: Is the vitamin D content adequate to satisfy the dietary requirement for vitamin D?. J Steroid Biochem Mol Biol. 2007 Mar;103(3-5):642-4. doi: 10.1016/j.jsbmb.2006.12.010. Epub 2007 Jan 30. PMID: 17267210; PMCID: PMC2698592.
3. Polzonetti V, Pucciarelli S, Vincenzetti S, Polidori P. Dietary Intake of Vitamin D from Dairy Products Reduces the Risk of Osteoporosis. Nutrients. 2020 Jun 10;12(6):1743. doi: 10.3390/nu12061743. PMID: 32532150; PMCID: PMC7353177.
4. Kühn J, Schutkowski A, Kluge H, Hirche F, Stangl GI. Free-range farming: a natural alternative to produce vitamin D-enriched eggs. Nutrition. 2014 Apr;30(4):481-4. doi: 10.1016/j.nut.2013.10.002. Epub 2013 Oct 14. PMID: 24607306.
5. Cardwell G, Bornman JF, James AP, Black LJ. A Review of Mushrooms as a Potential Source of Dietary Vitamin D. Nutrients. 2018 Oct 13;10(10):1498. doi: 10.3390/nu10101498. PMID: 30322118; PMCID: PMC6213178.
6. Cortese M, Riise T, Bjørnevik K, Holmøy T, Kampman MT, Magalhaes S, Pugliatti M, Wolfson C, Myhr KM. Timing of use of cod liver oil, a vitamin D source, and multiple sclerosis risk: The EnvIMS study. Mult Scler. 2015 Dec;21(14):1856-64. doi: 10.1177/1352458515578770. Epub 2015 May 6. PMID: 25948625; PMCID: PMC4657387.
