What Vitamin D Dosage Is Best? - Healthline

Có thể bạn quan tâm

HealthlineSubscribe

Nutrition

Evidence BasedWhat Vitamin D Dosage Is Best?

Medically reviewed by Mia Armstrong, MD — Written by Ryan Raman, MS, RD — Updated on December 20, 2024

Basics
Requirements
Deficiency
Sources
Increased needs
Toxicity
FAQ
Bottom line

Vitamin D dosage recommendations can vary depending on several factors, including your age, skin color, medical history, and where you live.

Vitamin D is commonly known as the “sunshine vitamin.”

That’s because your skin makes vitamin D when it is exposed to sunlight.

Getting enough vitamin D is important for optimal health. It helps maintain strong and healthy bones, aids your immune system, and may help protect against many harmful conditions.

Despite its importance, roughly 41% of people in the United States have a vitamin D insufficiency. Rates of vitamin D deficiency are higher for women, non-Hispanic Black people, and individuals ages 20–29.

There are several other groups of people that have higher vitamin D needs because of their age, where they live, and certain medical conditions.

This article will help you discover how much vitamin D you need daily.

What is vitamin D and why is it important?

Vitamin D belongs to the family of fat-soluble vitamins, which include vitamins A, D, E, and K. These vitamins are absorbed well with fat and are stored in the liver and fatty tissues.

There are two main forms of vitamin D in the diet:

Vitamin D2 (ergocalciferol): found in plant foods like mushrooms
Vitamin D3 (cholecalciferol): found in animal foods like salmon, cod, and egg yolks

However, sunlight is the best natural method of obtaining vitamin D3. The ultraviolet (UV) rays from sunlight convert cholesterol in your skin into vitamin D3.

Before your body can use dietary vitamin D, it must be “activated” through a series of steps.

First, the liver converts dietary vitamin D into the storage form of vitamin D. This is the form that is measured in blood tests. Later, the storage form is converted by the kidneys to the active form of vitamin D that’s used by the body.

Though both vitamin D2 and vitamin D3 can increase blood levels of vitamin D, some research suggests that vitamin D3 is more effective.

The main role of vitamin D in the body is to manage blood levels of calcium and phosphorus. These minerals are important for healthy bones.

Research also shows that vitamin D aids your immune system and may reduce your risk of heart disease and certain cancers.

A low blood level of vitamin D is linked to a greater risk of fractures and falls, heart disease, multiple sclerosis, several cancers, and even death.

How much vitamin D do you need for optimal health?

In the United States, current guidelines suggest that consuming 400–800 International Units (IU), or 10–20 micrograms (mcg), of vitamin D should meet the needs of 97%–98% of all healthy people.

However, many experts believe the guidelines are far too low and point out that there may have been a statistical error in the data originally used to estimate the recommended dietary allowance (RDA).

Your vitamin D needs depend on a variety of factors. These include your age, skin color, current blood vitamin D levels, location, sun exposure, and more.

To reach blood levels linked to better health outcomes, many studies have shown that you need to consume more vitamin D than the guidelines recommend.

For instance, one review of 17 studies found that vitamin D deficiency was associated with a significantly higher risk of developing colorectal cancer.

Another study found that taking people who have obesity have a greater risk of having vitamin D deficiency, so the dose should be adjusted according to size.

What’s more, a recent analysis found that having lower blood levels of vitamin D was associated with an increased risk of heart disease.

Keep in mind that it’s important not to consume more than 4,000 IU of vitamin D without a doctor’s permission, as it exceeds the safe upper limits of intake and is not linked to additional health benefits.

How do you know if you have a vitamin D deficiency?

A vitamin D deficiency can only be discovered through blood tests that measure levels of storage vitamin D, known as 25(OH)D.

According to the Institute of Medicine (IOM), the following values determine your vitamin D status:

Deficient: levels less than 12 nanograms per milliliter (ng/mL), or 30 nanomoles per liter (nmol/L)
Insufficient: levels between 12–20 ng/mL (30–50 nmol/L)
Sufficient: levels between 20–50 ng/mL (50–125 nmol/L)
High: levels greater than 50 ng/mL (125 nmol/L)

However, several older studies have found that a blood level of 30 ng/mL (75 nmol/L) could be even better for preventing fractures, falls, and certain cancers.

Additionally, some other organizations, such as the Endocrine Society, define blood levels of vitamin D lower than 30 ng/mL (75 nmol/L) as a vitamin D deficiency.

Sources of vitamin D

Getting plenty of sunlight is the best way to increase your blood vitamin D levels.

That’s because your body makes dietary vitamin D3 out of the cholesterol in the skin when it is exposed to the sun’s UV rays.

However, people who don’t live in sunny countries need to consume more vitamin D through foods and supplements.

Generally speaking, very few foods are great sources of vitamin D. However, the following foods are exceptions:

Cod liver oil: 1 tablespoon, or 14 grams (g), contains 170% of the Daily Value (DV)
Swordfish, cooked: 3 ounces (oz), or 85 g, contain 71% of the DV
Salmon, cooked: 3 oz (85 g) contain 56% of the DV
Canned tuna, drained: 3 oz (85 g) contain 29% of the DV
Beef liver, cooked: 3 oz (85 g) contain 5% of the DV
Egg yolks, large: 1 yolk contains 5% of the DV

Mushrooms also produce a significant amount of vitamin D2 when exposed to sunlight or UV light.

In fact, 1 cup (70 g) of raw white mushrooms provides less than 1% of the DV for vitamin D. Meanwhile, the same amount of UV-exposed raw white mushrooms contains nearly 92% of the DV.

If you’re choosing a vitamin D supplement, be sure to find one that contains D3 (cholecalciferol), as it may be more effective at raising your blood levels of vitamin D.

Some people need more vitamin D

There are certain groups of people who need more dietary vitamin D than others.

These include older people, those with darker skin, people who live far from the equator and those with certain medical conditions.

Older adults

There are many reasons why people need to consume more vitamin D with age.

For starters, your skin gets thinner as you grow older. This makes it harder for your skin to make vitamin D3 when it is exposed to sunlight.

Older people also often spend more time indoors. This means they get less exposure to sunlight, which is the best way to naturally boost vitamin D levels.

Additionally, your bones become more fragile with age. Maintaining adequate blood levels of vitamin D can help preserve bone mass with age and may protect against fractures.

People with darker skin

Research shows that people with darker skin are more prone to vitamin D deficiency.

This is because they have more melanin in their skin — a pigment that helps determine skin color. Melanin helps protect the skin from the sun’s UV rays.

However, it also reduces the body’s ability to make vitamin D3 from the skin, which can make you prone to deficiency.

If you have a vitamin D deficiency, a doctor can recommend an appropriate dosage for supplementation based on your vitamin D blood levels.

Those who live farther away from the equator

Countries close to the equator get plenty of sunlight all year round. Conversely, countries farther away from the equator get less sunlight all year round.

This can cause low blood vitamin D levels, especially during winter months when there is even less sunlight.

For instance, a 2007 study of Norwegians discovered that they don’t produce much vitamin D3 from their skin during the winter months of October to March.

If you live far from the equator, then you need to get more vitamin D from your diet and supplements. According to one older review, many experts agree that at least 1,000 IU (25 mcg) of vitamin D3 daily is needed in situations where there is no exposure to sunlight.

People with medical conditions that reduce fat absorption

Because vitamin D is fat-soluble, it relies on the gut’s ability to absorb fat from the diet.

Thus, people who have medical conditions that reduce fat absorption are prone to vitamin D deficiencies. These include inflammatory bowel disease (Crohn’s disease and ulcerative colitis), liver disease, and people who have had bariatric surgery.

People with the above conditions are often advised to take vitamin D supplements in an amount prescribed by a doctor.

Can you take too much vitamin D?

While it is possible to take too much vitamin D, toxicity is very rare.

In fact, you would need to take extremely high doses of 50,000 IU (1,250 mcg) or more for a long period of time.

It’s also worth noting that it is impossible to overdose on vitamin D from sunlight.

However, it’s best to consult with a doctor or dietitian for personalized recommendations on how much vitamin D you should take, depending on your needs.

Frequently asked questions

How much vitamin D do we need?

Males and females need the same amount of vitamin D, around 15 mcg (600 IU) daily. However, it can be hard to know how much your body is taking in or creating, as both food and sunlight contribute.

What’s better: Vitamin D2 or D3?

Vitamin D3 appears to be more effective than vitamin D2 at helping the body reach its necessary vitamin D levels. For this reason, if you’re taking supplements, vitamin D3 may be your best choice.

What dose of vitamin D3 supplements do I need?

If you’re taking supplements, how much you need to take will depend on your individual requirements. A doctor can advise you on this.

How much vitamin D is too much?

If you are taking supplements, you should not take more than 50 ng/mL per day. Levels of vitamin D in the blood are too high when they are over 125 nmol / L.

How do I take vitamin D correctly?

First, you will need to discuss your specific needs with a doctor. They will advise on whether or not you need supplements and how much to take. If you are using supplements, always follow the instructions on the package.

The bottom line

Getting enough vitamin D from sunlight and foods is necessary for optimal health.

It helps maintain healthy bones, aids your immune system, and may reduce the risk of many harmful diseases. Yet despite its importance, many people don’t get enough vitamin D.

In addition, older people, people with darker skin, those who live farther away from the equator, and people who can’t absorb fat properly have higher dietary vitamin D needs.

The current recommendations suggest consuming 400–800 IU (10–20 mcg) of vitamin D per day.

However, people who need more vitamin D can safely consume 1,000–4,000 IU (25–100 mcg) daily. Consuming more than this is not advised unless prescribed by a healthcare professional.

How we reviewed this article:

SourcesHistoryHealthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical journals and associations. We only use quality, credible sources to ensure content accuracy and integrity. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

Amrein K, et al. (2020). Vitamin D deficiency 2.0: an update on the current status worldwide.https://pmc.ncbi.nlm.nih.gov/articles/PMC7091696/
Asif A, et al. (2023). Vitamin D toxicity.https://www.ncbi.nlm.nih.gov/books/NBK557876/
Barbarawi M, et al. (2019). Vitamin D supplementation and cardiovascular disease risks in more than 83,000 individuals in 21 randomized clinical trials.https://pmc.ncbi.nlm.nih.gov/articles/PMC6584896/
Billington EO, et al. (2020). Safety of high-dose vitamin D supplementation: Secondary analysis of a randomized controlled trial.https://academic.oup.com/jcem/article/105/4/1261/5634116
Bischoff-Ferrari HA, et al. (2006). Estimation of optimal serum concentrations of 25-hydroxyvitamin D for multiple health outcomes.https://pubmed.ncbi.nlm.nih.gov/16825677/
Cardwell G, et al. (2018). A review of mushrooms as a potential source of dietary vitamin D.https://pmc.ncbi.nlm.nih.gov/articles/PMC6213178/
Carlberg C. (2022). Vitamin D and pigmented skin.https://pmc.ncbi.nlm.nih.gov/articles/PMC8781604/
Chapter: 5 Dietary reference intakes for adequacy: Calcium and vitamin D. (2011).https://nap.nationalacademies.org/read/13050/chapter/7
Chauhan K, et al. (2023). Vitamin D.https://www.ncbi.nlm.nih.gov/books/NBK441912/
Cosentino N, et al. (2021). Vitamin D and cardiovascular disease: Current evidence and future perspectives.https://pmc.ncbi.nlm.nih.gov/articles/PMC8541123/
Cui A, et al. (2022). Prevalence, trend, and predictor analyses of vitamin D deficiency in the US population, 2001–2018.https://pmc.ncbi.nlm.nih.gov/articles/PMC9573946/
Daily value on the nutrition and supplement facts labels. (2024).https://www.fda.gov/food/nutrition-facts-label/daily-value-nutrition-and-supplement-facts-labels
Dominguez LJ, et al. (2021). Vitamin D sources, metabolism, and deficiency: Available compounds and guidelines for its treatment.https://pmc.ncbi.nlm.nih.gov/articles/PMC8074587/
Fan X, et al. (2020). Vitamin D status and risk of all-cause and cause-specific mortality in a large cohort: Results from the UK biobank.https://pubmed.ncbi.nlm.nih.gov/32620963/
FoodData Central search. (2024).https://fdc.nal.usda.gov/food-search
Giustina A, et al. (2022). Vitamin D in the older population: a consensus statement.https://pmc.ncbi.nlm.nih.gov/articles/PMC9607753/
Holick MF. (2015). Vitamin D Is not as toxic as was once thought: A historical and an up-to-date perspective.https://www.mayoclinicproceedings.org/article/S0025-6196(15)00244-X/fulltext
Jani R, et al. (2021). Circulating 25-hydroxy-vitamin D and the risk of cardiovascular diseases. Systematic review and meta-analysis of prospective cohort studies.https://pubmed.ncbi.nlm.nih.gov/34656382/
Kong SH, et al. (2022). Effect of vitamin D supplementation on risk of fractures and falls according to dosage and interval: A meta-analysis.https://pmc.ncbi.nlm.nih.gov/articles/PMC9081312/
Lu Z, et al. (2009). An evaluation of the vitamin D3 content in fish: Is the vitamin D content adequate to satisfy the dietary requirement for vitamin D?https://pmc.ncbi.nlm.nih.gov/articles/PMC2698592/
Martens PJ, et al. (2020). Vitamin D’s effect on immune function.https://pmc.ncbi.nlm.nih.gov/articles/PMC7281985/
Martineau AR, et al. (2019). Differential effects of oral boluses of vitamin D2 vs vitamin D3 on vitamin D metabolism: A randomized controlled trial.https://pmc.ncbi.nlm.nih.gov/articles/PMC6797055/
McCullough ML, et al. (2018). Circulating vitamin D and colorectal cancer risk: An international pooling project of 17 cohorts.https://pmc.ncbi.nlm.nih.gov/articles/PMC6376911/
Mendes MM, et al. (2019). Impact of high latitude, urban living and ethnicity on 25-hydroxyvitamin D status: A need for multidisciplinary action?https://pubmed.ncbi.nlm.nih.gov/30610914/
Papadimitriou DT. (2017). The big vitamin D mistake.https://pmc.ncbi.nlm.nih.gov/articles/PMC5541280/
Reddy P, et al. (2022). Biochemistry, fat soluble vitamins.https://www.ncbi.nlm.nih.gov/books/NBK534869/
Schlessinger DI, et al. (2023). Biochemistry, melanin.https://www.ncbi.nlm.nih.gov/books/NBK459156/
Segheto KJ, et al. (2021). Vitamin D and bone health in adults: a systematic review and meta-analysis.https://pubmed.ncbi.nlm.nih.gov/34378711/
Shahnazari B, et al. (2019). Comparison of the effect of vitamin D on osteoporosis and osteoporotic patients with healthy individuals referred to the Bone Density Measurement Center.https://pubmed.ncbi.nlm.nih.gov/30956224/
Sintzel MB, et al. (2017). Vitamin D and multiple sclerosis: A comprehensive review.https://pmc.ncbi.nlm.nih.gov/articles/PMC5990512/
Vieth R. (2011). Why the minimum desirable serum 25-hydroxyvitamin D level should be 75 nmol/L (30 ng/ml).https://pubmed.ncbi.nlm.nih.gov/21872808/
Visser M, et al. (2006). Low serum concentrations of 25-hydroxyvitamin D in older persons and the risk of nursing home admission.https://pubmed.ncbi.nlm.nih.gov/16960177/
Vitamin D: Fact sheet for health professionals. (2024).https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
Wang H, et al. (2017). Vitamin D and chronic diseases.https://pmc.ncbi.nlm.nih.gov/articles/PMC5440113/
Yi Z, et al. (2021). Effect of vitamin D deficiency on liver cancer risk: A systematic review and meta-analysis.https://pmc.ncbi.nlm.nih.gov/articles/PMC8325142/
Young AR, et al. (2020). Melanin has a small inhibitory effect on cutaneous vitamin D synthesis: A comparison of extreme phenotypes.https://www.jidonline.org/article/S0022-202X(19)33565-1/fulltext
Žmitek K, et al. (2020). Efficiency of vitamin D supplementation in healthy adults is associated with body mass index and baseline serum 25-hydroxyvitamin D level.https://pmc.ncbi.nlm.nih.gov/articles/PMC7284348/

Share this article

Evidence Based

This article is based on scientific evidence, written by experts and fact checked by experts.

Our team of licensed nutritionists and dietitians strive to be objective, unbiased, honest and to present both sides of the argument.

This article contains scientific references. The numbers in the parentheses (1, 2, 3) are clickable links to peer-reviewed scientific papers.

Medically reviewed by Mia Armstrong, MD — Written by Ryan Raman, MS, RD — Updated on December 20, 2024

Health Conditions

Condition Spotlight

Wellness Topics

Product Reviews

Featured Programs

Featured

Lessons

Newsletters

Lifestyle Quizzes

Health News

This Just In

Top Reads

Video Series

Find Your Bezzy Community

Follow us on social media

Nutrition

Nutrition

What is vitamin D and why is it important?

How much vitamin D do you need for optimal health?

How do you know if you have a vitamin D deficiency?

Sources of vitamin D

Some people need more vitamin D

Older adults

People with darker skin

Those who live farther away from the equator

People with medical conditions that reduce fat absorption

Can you take too much vitamin D?

Frequently asked questions

How much vitamin D do we need?

What’s better: Vitamin D2 or D3?

What dose of vitamin D3 supplements do I need?

How much vitamin D is too much?

How do I take vitamin D correctly?

The bottom line

How we reviewed this article:

Evidence Based

Read this next

Liên Hệ