Are you getting enough vitamin D every day? Vitamin D plays a key role in bone health, immune function, and eye health.
Read on for the links between vitamin D and eye health and dry eyes and discover some of the best vitamin D rich food.
Vitamin D and Eye Health
Vitamin D refers to two similar molecules, ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3). The skin produces most vitamin D when exposed to the sun. Certain foods are also rich in vitamin D.
A fat-soluble vitamin, vitamin D performs major biological functions in the body, including regulating the immune system and insulin, controlling cell proliferation, and improving calcium absorption.
Another study on postmenopausal women found that vitamin D from supplements decreased the risk of early AMD. What’s more, a 2017 study notes that the vitamin may preserve the function of retinal cells in the macula of the eye.
A leading cause of irreversible vision loss, AMD damages the central portion of the eye, making reading or driving difficult. More than 170 million people around the world suffer from AMD.
Vitamin D deficiency is also associated with diabetes, cardiovascular disease, inflammatory disease, and other conditions that may give rise to serious eye-health complications, such as diabetic retinopathy.
Vitamin D and Dry Eyes
A 2016 Korean study associated a lack of vitamin D with dry eye syndrome in adults. Vitamin D improves the quality of the tear film that lubricates the eye. It contributes to the healthy functioning of the lacrimal glands and has other eye health benefits.
A 2020 study published in the Indian Journal of Ophthalmology concluded that vitamin D may help with treating dry eyes.
You may not get enough vitamin D if you live in an urban setting, don’t get enough sun exposure (such as during winter months), or because of nutritional deficiencies. Having darker skin, using sunscreen, or being older may also reduce vitamin D absorption from sunlight.
But eating foods high in vitamin D more often can help complement the vitamin D your body makes when exposed to the sun.
Vitamin D Rich Foods You Should Eat More Of
Vitamin D3 comes mainly from animals while D2 comes mainly from plants. It’s good to distinguish between the two even if food labeling often doesn’t. Ideally, you want to eat both. If you have to choose, D3 is associated with better absorption in the body.
1. Oily Fish
Trout and oily fish such as salmon, sardines, mackerel, and herring are rich sources of vitamin D3. They have omega 3-fatty acids too, which can also help improve the quality of the tear film.
Whether you serve oily fish as your main course, add it to salads, or use it in sandwiches, oily fish is a reliable source of vitamin D3.
2. Mushrooms Exposed to UV Light
Mushrooms are the only vegetables high in vitamin D, provided they’ve grown in the sunlight or under a sunlamp. Mushrooms exposed to UV light provide a lot more of this vitamin than those grown in the shade.
While most mushrooms carry some vitamin D, specific varieties pack significantly more. For example, while raw shiitake or oyster mushrooms have negligible amounts of this vitamin, white, brown, or portabella mushrooms can help you meet the recommended daily allowance of Vitamin D (20 mcg). Raw maitake mushrooms are also a rich source of Vitamin D.
3. Milk (Fortified)
Cow’s milk doesn’t contain enough vitamin D naturally, but it’s often fortified with this vitamin. This makes it a dependable source of the sun vitamin. Plant-based milk such as almond, soy, or rice milk is often enriched with vitamins as well.
4. Dairy Products (Fortified)
Cheese, yogurt, and other dairy products fortified with vitamin D deserve a mention too. In addition to helping to keep your eyes healthy, they may also reduce the risk of osteoporosis.
5. Tofu (Fortified)
Tofu is another food that’s often fortified with vitamin D. How much of this vitamin you get per serving depends on the product you buy.
But you can get more than your daily dose per 100 grams of tofu. For vegetarians and vegans, fortified tofu is one of the most accessible vitamin D sources.
6. Breakfast Cereals (Fortified)
Breakfast cereals including muesli have this vitamin too. You can pair them with milk to start your day with a healthy vitamin D boost.
But it’s important to pay attention to the other ingredients. Overly sweet breakfast cereals may cause a blood sugar spike you may want to avoid.
7. Fortified Orange Juice
You’ll be hard-pressed to find fruits high in vitamin D. But the good news is that one cup of orange juice fortified with this vitamin can provide 100% of the daily recommended dose.
You may also find other fruit juices enriched with this vitamin in stores to compensate for the absence of vitamin D rich fruits. Choose all-natural if possible, as juices with added sugar may increase the risk of diabetes, a condition that may damage eyesight.
8. Other Foods Fortified with Vitamin D
Other Vitamin D fortified foods include bread, plant-based drinks and juices, vegan substitutes, cereal bars, and margarine. You may want to try these too. But always make sure to check ingredients.
You want to avoid hydrogenated fats, unnecessary sugar, and other ingredients that may affect your long-term health and, with it, your eyesight.
Don’t Forget Your Eye Health Supplements
Vitamin D supplements can also help you complement your daily intake of the sun vitamin, especially during the colder months. You can find them on their own or as part of vitamin mixes.
Having some at hand can be a good idea on those days when you’re not sure you’ve got enough vitamin D from the sun or through food.
Vitamin D is important for your eyesight, but don’t forget about antioxidants, lutein, beta-carotene, zeaxanthin, and the other nutrients your eyes need to stay healthy. Keeping track of your daily intake of eye nutrients doesn’t have to be tricky.
After all, this is why we created SightC, a full-spectrum vision health supplement informed by decades of experience treating patients with vision problems. Try it out if you haven't already.