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You might figure that you’re getting enough vitamin D by downing a glass of milk at breakfast or taking your regular walk on sunny mornings, but that’s not necessarily so. It’s actually smart to track exactly how much vitamin D you get from your diet because it can be hard to consume enough for your body to function at its best.
Health benefits of vitamin D
What does the right amount of vitamin D do for your health? “Vitamin D plays a role in many processes in the body,” says Marisa Moore, M.B.A., R.D.N., L.D., a nutritionist in Atlanta. “It’s a key regulator in the immune system and plays an important role in regulating our mood and sleep.” Plus, according to Mayo Clinic, if your body doesn’t have enough vitamin D, it can’t absorb calcium, which keeps your bones strong and healthy. The vitamin may also be crucial for muscle strength and might even help prevent cancer and type-2 diabetes, the Centers for Disease Control (CDC) says.
However, an overview from Oregon State University’s Linus Pauling Institute Information Center found that more than 94% of Americans don’t get enough vitamin D on a daily basis. What’s more, the National Institutes of Health’s National Center for Biotechnology Information reports that not getting enough vitamin D is linked to a number of major health problems, including cardiovascular disease, autoimmune disease, and depression.
How much vitamin D do you need in a day?
According to the National Institutes of Health’s Office of Dietary Supplements, the answer depends on your age. The NIH offers the following guidance on vitamin D requirements for healthy people:
- Birth to 12 months: 10 mcg (400 IU)
- Children 1 to 13 years: 15 mcg (600 IU)
- Teens 14 to 18 years: 15 mcg (600 IU)
- Adults 19 to 70 years: 15 mcg (600 IU)
- Adults 71 years and older: 20 mcg (800 IU)
- Pregnant and breastfeeding teens and women15 mcg (600 IU)
If you have a vitamin D deficiency, your doctor may decide that you need more. “The Tolerable Upper Intake Level (UL) of vitamin D for adults is 4,000 IU, or 100 mcg, per day, but some people may be prescribed higher doses temporarily to correct a deficiency,” says Dawn Jackson Blatner, R.D.N., C.S.S.D., a nutritionist in Chicago.
Not everyone should take vitamin D, though. “Whether you actually need a supplement depends on what your daily diet contains,” says Bonnie Taub-Dix, R.D.N., host of the Media Savvy Podcast, creator of BetterThanDieting.com, author of Read It Before You Eat It: Taking You from Label to Table. “Other factors include your age, the state of your health, and the amount of sun exposure you get.”
To see what your baseline is, check in with your doctor. They can assess your vitamin D levels as well as your diet to point you in the right direction. “A simple blood test takes the guesswork out of your vitamin D level,” Blatner says. “Your healthcare provider can then let you know how much vitamin D you need, whether to supplement, and how to avoid taking more vitamin D than necessary,”
Who’s at risk for vitamin D deficiency?
Women who are pregnant or have certain health conditions should be especially vigilant about getting enough vitamin D. “Deficiency is often seen in women with pre-eclampsia, gestational diabetes, autoimmune conditions like Hashimoto thyroiditis, and some cancers, including breast cancer,” says Sue-Ellen Anderson-Haynes, M.S., R.D.N., CDCES, a spokesperson for the Academy of Nutrition and Dietetics and the owner of 360Girls&Women and B.E.A.T. Gestational Diabetes.
Breastfeeding moms should also be aware that breast milk doesn’t provide babies with enough vitamin D. This means you should make sure your baby gets a supplement, as Carol Haggans, M.S., R.D., a spokesperson for the NIH Office of Dietary Supplements, previously told Good Housekeeping.
People with darker skin can also be at risk of deficiency. “Darker skin contains more melanin, or pigment,” says Sue-Ellen Anderson-Haynes, MS, RDN, CDCES, a spokesperson for the Academy of Nutrition and Dietetics and the owner of 360Girls&Women and B.E.A.T. Gestational Diabetes. “The more melanin in your skin, the harder that UVB rays from the sun need to work to penetrate it. This means people with darker skin need more sun exposure to avoid becoming vitamin D deficient. People who stay indoors most of the time, have liver or kidney conditions, or who take certain medications—like steroids, cholesterol-lowering drugs, or weight loss medication—may also be at risk for vitamin D deficiency.”
You also have higher odds of having a vitamin D deficiency if:
- you have Crohn's disease, ulcerative colitis, and celiac disease, conditions that make it difficult to absorb fat from food.
- you have excess body fat because it can bind to vitamin D and prevent your blood from absorbing it properly
- you’ve had gastric bypass surgery because your small intestine may not be able to absorb enough of the nutrient post-surgery
- you’re a senior because your skin may not absorb enough vitamin D and your kidneys may not be able to convert it in your body as well as someone younger
Can you take too much vitamin D?
Yes. “Vitamin D is essential, but more isn’t always better,” says Blatner. In fact, too much vitamin D can actually be dangerous. According to Harvard Medical School, vitamin D doesn’t dissolve in water, so you can’t pee out any excess. Instead, it can build up in your blood and tissues and create health problems.
“Vitamin D toxicity, or hypervitaminosis D, is a serious condition that causes calcium to increase and accumulate in your blood,” says Anderson-Haynes. “This can lead to GI upset, fatigue, weakness, frequent urination and kidney stones.”
However, those negative outcomes are usually not a concern unless you’re taking supplements. “Too much vitamin D almost always comes from excessive supplement use, not from too much food or sunlight,” says Blatner.
Can you get enough vitamin D from food?
“Because vitamin D is naturally found in only a limited number of foods, it can be challenging to get enough vitamin D without a supplement—but it is possible,” says Taub-Dix. “Fatty fish such as salmon, trout, sardines, mackerel, and tuna are among the best sources. Egg yolks and mushrooms exposed to ultraviolet light provide some vitamin D, too. Also, fortified foods like vitamin D in milk, fortified plant-based beverages, some yogurts, orange juices, and breakfast cereals are other options.”
Some of these picks actually do nutritional double duty. “Vitamin D-rich foods come with other health benefits,” says Moore. “For example, fatty fish is not only an excellent source of vitamin D, but also a source of protein and omega-3 fatty acids, which support your health. Also, UV-exposed mushrooms are an excellent plant-based vitamin D source, plus they provide other nutrients like potassium, which supports healthy blood pressure.”
The way you consume a vitamin D-rich food can also increase the good it does for you. “Since vitamin D is fat-soluble, your body generally absorbs it best when it is consumed with a meal or snack that contains some fat—like a little olive oil, avocado, nuts, eggs, dairy, or fatty fish,” says Taub-Dix.
Can you get enough vitamin D from the sun?
It’s true that sun exposure can help boost your level—UV rays are absorbed by your skin and move to your liver, where they're converted to vitamin D. However, you need consistent exposure to get sufficient benefits. A 2026 study from the UK found that trying to get more sun in the summer doesn’t sufficiently make up for a lack of vitamin D in some people who have a low level of both vitamin D and sun exposure throughout the rest of the year. On top of that, if you wear sunscreen (which you should!), it blocks some of the UV rays needed for your body to produce vitamin D.
The bottom line
We all need vitamin D, but it can be difficult to get enough from food alone. By working with your doctor, you can find out if you need more and if so, the best way to up your levels of the nutrient. Don’t rely on guesswork—get the facts and then reap the health benefits of vitamin D.
Stefani (she/her) is a registered dietitian, a NASM-certified personal trainer and the director of the Good Housekeeping Institute Nutrition and Fitness Lab, where she oversees all nutrition and fitness-related content, testing and evaluation. She holds a master’s degree in clinical nutrition from New York University, as well as advanced certifications as a Women's Fitness Specialist and a Behavior Change Specialist. Stefani is dedicated to providing readers with evidence-based content to encourage informed food choices and healthy living. She is an avid CrossFitter and a passionate home cook who loves spending time with her big fit Greek family.
