Vitamin D3 – 5000 IU: Benefits of High-Dose D3 Supplementation

While vitamin D supplements are among the most popular dietary supplements, many people don’t take high enough vitamin D3 doses to prevent deficiency and maintain healthy levels.

Discover the health benefits of taking 5,000 IU of vitamin D3 daily and find out why you should always combine vitamin D3 with vitamin K2.

What is vitamin D3?

Vitamin D3, also known as the sunshine vitamin, is produced when the skin is exposed to ultraviolet B (UVB) rays in sunlight.

UVB light exposure triggers a chain of complex biochemical reactions that convert previtamin D into active vitamin D3 .

“The body stores vitamin D3 in the liver and fat cells, which serve as a reservoir that the body can draw upon to compensate for short periods without sunlight exposure,” explains Dr. Berg. “However, prolonged lack of UVB radiation can deplete body stores and result in vitamin D insufficiency.”

The rate of vitamin D3 production can vary significantly from person to person and depends on many factors.

Older people and individuals with darker skin pigmentation may not generate adequate amounts of vitamin D3 despite plenty of sun exposure, which explains why older adults and those with darker skin tones are at risk of vitamin D deficiency .

Very few foods naturally contain vitamin D3, and dietary sources, including fatty fish, cod liver oil, egg yolks, beef liver, and fortified dairy products, typically don’t offer enough vitamin D3 to maintain a healthy vitamin D status.

Watch the video below to learn how much vitamin D you may need to maintain a healthy body.

Signs of vitamin D deficiency

Vitamin D regulates various physiological processes, which explains why a lack of adequate vitamin D3 can result in a wide range of symptoms.

Here are common signs of vitamin D deficiency:

• Frequent infections
• Fatigue
• Muscle aches
• Bone pain
• Soft and brittle bones
• Unexplained hair loss
• Acne
• Depression

How much vitamin D3 do you need?

It’s well established that vitamin D3 supplements are effective at raising and maintaining optimal vitamin D levels. However, current intake recommendations are conflicting.

While a factsheet published by the National Institutes of Health suggests a daily vitamin D dose of 600 IU, the American Academy of Family Physicians recommends 1,000 IU of vitamin D daily, and The Endocrine Society suggests that adults get between 1,500 and 2,000 IU of vitamin D per day.

So, how much vitamin D3 should you be taking?

“Your appropriate vitamin D3 dosage should always be guided by your blood concentrations of 25-hydroxyvitamin D, a blood marker that reflects your body’s overall vitamin D stores,” explains Dr. Berg.

Evidence published in Nutrients suggests that 25-hydroxyvitamin D concentrations of 40 ng/mL (100 nmol/L) or above indicate an optimal vitamin D status and that 600 IU of vitamin D isn’t enough to significantly raise vitamin D levels.

This aligns with research published in StatPearls that found that many adults require between 5,000 and 10,000 IU of vitamin D3 daily to correct a deficiency and maintain vitamin D levels.

If you are considering taking vitamin D to promote general health, it’s recommended to consult a healthcare provider to perform vitamin D testing, which helps determine your appropriate vitamin D3 dosage.

Alternatively, many pharmacies and health stores offer inexpensive finger-prick tests to evaluate vitamin D status.

Benefits of high-dose vitamin D3 (5,000 IU or more)

High-dose vitamin D3 supplementation of 5,000 IU or more is recommended for individuals with vitamin D deficiency and people at risk of low vitamin D absorption, such as older individuals and those with darker skin color.

In addition, people with certain health problems, including poor liver function, osteoporosis, Crohn’s disease, inflammatory bowel disease, and other autoimmune conditions, are at increased risk of vitamin D deficiency and can benefit from high doses of vitamin D3.

Taking between 5,000 and 10,0000 IU of vitamin D3 can enhance immune system functions and improve recovery time and health outcomes in various infectious diseases.

A study published in Nutrients investigated the effects of high-dose D3 supplementation in COVID patients and concluded, “The use of 5,000 IU vitamin D3 as an adjuvant therapy for COVID-19 patients with suboptimal vitamin D status is recommended.”

Risks of high-dose vitamin D3

While vitamin D3 is generally considered safe, it’s a fat-soluble vitamin that can accumulate in the body, and taking too much vitamin D for long periods can have toxic effects.

Excessive amounts of vitamin D supplementation, especially when taken by an individual with optimal vitamin D levels, can lead to vitamin D toxicity , characterized by 25-hydroxyvitamin D blood levels greater than 100 ng/mL (250 nmol/L).

Common symptoms of vitamin D toxicity include:

• Nausea and vomiting
• Gastrointestinal issues
• Unexplained weight loss
• Confusion
• Kidney stones
• Elevated blood calcium levels

To avoid the risk of vitamin D toxicity, it’s recommended to perform regular blood tests and adjust your vitamin D3 dosage accordingly.

In addition, it’s important to note that individuals with a medical history of sarcoidosis, primary hyperparathyroidism, or certain cancers are more likely to experience vitamin D-related side effects and shouldn’t take extra vitamin D without consulting a healthcare professional.

Why take vitamin D3 with vitamin K2

Combining vitamin D3 and K2 benefits calcium balance and lowers the risk of skeletal issues and cardiovascular disease.

Because vitamin D3 stimulates intestinal calcium absorption, it can cause elevated blood calcium concentrations, linked to an increased risk of arterial calcification—a primary risk factor for heart disease.

Vitamin K2 activates proteins that bind calcium in the blood and deposit it into bone and teeth. Not only does this promote skeletal and dental health, but it also lowers the risk of soft tissue calcification.

How much vitamin K2 you should take with vitamin D3 depends on your vitamin D3 dose. The ideal ratio of vitamin D3 to K2 is 1000:10 , and it’s recommended to take 10 mcg of vitamin K2 per 1000 IU of vitamin D3.

Five reasons to take vitamin D3

Vitamin D3 plays an essential role in calcium balance, immune defenses, nerve signal transmission, and neurotransmitter production.

Vitamin D is so critical for human health that many scientists suggest it should be classified as a hormone to emphasize the need to maintain optimal levels.

Here are five reasons to take vitamin D3.

1. Support cardiovascular health

Maintaining healthy vitamin D levels is associated with lower blood pressure and a reduced risk of cardiovascular disease.

It’s thought that vitamin D improves endothelial function, which promotes healthy blood vessels and lowers the risk of high blood pressure.

Vitamin D deficiency has been linked to narrowing blood vessels and vascular damage, significantly increasing the risk of atherosclerosis, heart attacks, and stroke.

2. Promote healthy bones

Vitamin D helps the body absorb calcium, an essential mineral needed for bone metabolism, and taking vitamin D3 in combination with vitamin K2 supports bone health and lowers the risk of skeletal issues.

Without adequate vitamin D levels, the body can only absorb a fraction of dietary and supplemental calcium, significantly increasing the risk of calcium deficiency linked to loss of bone mass, osteoporosis, and fractures.

3. Strengthen immune defenses

Vitamin D3 is needed to stimulate the activity of white blood cells, a group of immune cells that are the body’s main defense mechanism against infections and diseases.

Vitamin D also regulates how immune cells interact with each other, which is crucial for balanced immune responses and helps prevent the development of autoimmune diseases such as rheumatoid arthritis, psoriasis, and multiple sclerosis.

4. Lower cancer risk

Evidence published in Trends in Cancer Research found that optimal vitamin D levels are associated with a lower risk of breast, colon, and prostate cancer.

Although more research is needed to confirm the role of vitamin D in cancer prevention, it’s believed that vitamin D enhances the ability of immune cells, such as Natural Killer cells, to eliminate potentially abnormal and or carcinogenic cells.

5. Support mental health

Vitamin D deficiency is linked to mood disorders such as depression, which explains why seasonal affective disorder (SAD) typically develops during winter months when adequate UVB exposure is limited.

Vitamin D stimulates the production of serotonin, a neurotransmitter that regulates moods, and imbalanced serotonin levels can lead to an increased risk of depression, anxiety, and attention deficit disorder (ADD).

Key takeaways

Vitamin D is vital for calcium absorption, skeletal and cardiovascular health, immune defenses, and mental well-being.

Evidence suggests that taking 600 IU of vitamin D isn’t enough and that it may require between 5,000 and 10,000 IU of vitamin D3 daily to correct a deficiency and to maintain healthy levels in individuals at risk of low vitamin D status.

Additional resources

FAQ

1. How much vitamin D3 do I need?

How much vitamin D3 you need depends on your vitamin D levels, age, skin tone, and health status.

Evidence suggests that many individuals require between 5,000 and 10,000 IU of vitamin D3 daily to achieve optimal 25-hydroxyvitamin D blood concentrations of 40 ng/mL (100 nmol/L) or above.

2. Can I take 5,000 IU of vitamin D3 every day?

Yes, taking 5,000 IU of vitamin D3 is generally considered safe and well-tolerated by most healthy adults.

3. What happens if I take 5,000 IU of vitamin D3 every day?

Taking 5,000 IU of vitamin D3 every day is beneficial to correct and prevent vitamin D deficiency and helps maintain optimal vitamin D levels.

High-dose vitamin D3 supplementation has been found to promote bone health, strong immune defenses, and healthy blood pressure and is linked to a reduced risk of depression, osteoporosis, and certain cancers.

4. Is 5,000 IU too high for vitamin D3?

5,000 IU of vitamin D3 is an ideal dose for individuals with vitamin D deficiency and those at risk of poor vitamin D absorption, including older adults and people with darker skin tones.

High-dose vitamin D3 supplementation may also benefit people with certain medical conditions, such as poor bone health, acne, hair loss, liver problems, and autoimmune diseases.

5. How quickly does 5,000 IU of vitamin D3 take to work?

Most people notice improved well-being within three to four weeks of consistent high-dose vitamin D3 supplementation.

However, individuals with vitamin D deficiency may experience noticeable effects within one to two weeks of taking 5,000 IU of vitamin D3.

6. What is the best time to take vitamin D3 5,000 IU?

Because vitamin D3 is fat-soluble, taking vitamin D with a meal helps improve its absorption, and most people find it convenient to take vitamin D supplements with breakfast or lunch.

There is evidence that vitamin D3 promotes healthy sleep, and taking vitamin D3 before bedtime may benefit individuals with sleep apnea, insomnia, or other sleep-related problems.

7. What are the side effects of 5,000 IU of vitamin D3?

While taking 5,000 IU of vitamin D3 isn’t linked to side effects, it’s important to note that vitamin D3 enhances intestinal calcium absorption, which can lead to elevated blood calcium levels and an increased risk of heart disease.

That’s why it’s crucial to take vitamin D3 in combination with vitamin K2, a fat-soluble vitamin that maintains healthy blood calcium concentrations by depositing calcium into bone and teeth.

8. Is it safe to take 5,000 IU of vitamin D3?

Taking 5,000 IU of vitamin D3 is an effective strategy to maintain a healthy vitamin D status and is generally considered safe and well tolerated.

It’s recommended to regularly perform blood tests to evaluate vitamin D blood concentrations and adjust vitamin D3 doses accordingly.

9. How much vitamin K2 should I take with 5,000 IU of vitamin D3?

The best ratio of vitamin D3 and K2 is 1000:10, meaning you should take 50 mcg of vitamin K2 with 5000 IU of vitamin D3.

Sources

1. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/
2. https://www.aafp.org/pubs/afp/issues/2013/0215/od2.html
3. https://endocrinenews.endocrine.org/nov-2014-just-right-how-much-vitamin-d-is-enough/
4. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3257679/
5. https://www.ncbi.nlm.nih.gov/books/NBK532266/
6. https://pubmed.ncbi.nlm.nih.gov/34202578/
7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6201256/

The Health Benefits of Vitamin D3

Vitamin D3 ( cholecalciferol) has a few health benefits, including helping the body absorb calcium. Foods such as fish, beef liver, eggs, and cheese naturally contain vitamin D3. It can also be produced in the skin following exposure to ultraviolet (UV) radiation from the sun.

Supplement forms of vitamin D3 are also available and may be used for general health, as well as the treatment or prevention of vitamin D deficiency.

Vitamin D3 is one of two types of vitamin D. It differs from vitamin D2 (ergocalciferol) in both its structure and sources.

The article explains what vitamin D supplements do and the benefits/drawbacks of vitamin D3 specifically. It also lists other important sources of vitamin D3.

Why You Need Vitamin D

Vitamin D, also referred to as calciferol , is a fat-soluble vitamin (meaning one that is broken down by fat and oils in the gut). It is commonly referred to as the “sunshine vitamin” because the D3 type can be naturally produced in the body following exposure to the sun.

Vitamin D has many functions in the body, chief of which include:

• Bone growth
• Bone remodeling
• Regulation of muscle contractions
• Conversion of blood glucose (sugar) into energy

Not getting enough vitamin D can lead to an array of health concerns, including:

• Delayed growth in kids
• Rickets in kikds
• Osteomalacia (loss of bone minerals) in adults and adolescents
• Osteoporosis (porous, thinning bones) in adults

How Much Vitamin D Do I Need?

Current guidelines from the National Institutes of Health recommend that people ages 1 to 70 years should get 600 international units (IUs) of vitamin D per day from all sources. Adults over 70 need 800 IUsdaily.

How Do I Know If I Need More Vitamin D?

If you do not obtain enough vitamin D to meet the body’s needs you are considered to have a vitamin D deficiency. This can be diagnosed through blood testing.

However, the U.S. Preventive Services Task Force does not recommend routine vitamin D screening in adults without symptoms of deficiency.

Not everyone who is low in vitamin D experiences symptoms. Those who do may notice:

• Muscle and/or bone pain
• Muscle weakness
• History of fractures
• Muscle twitching

If you suspect you could be vitamin D deficient, ask your healthcare provider to test your blood levels or take an at-home test.

Causes for vitamin D deficiency are many, including diseases or conditions that limit fat absorption and the breakdown of vitamin D in the gut. As such, you are at greater risk for vitamin D deficiency if you have:

• Celiac disease
• Crohn’s disease
• Cystic fibrosis
• Gastric bypass surgery
• Liver disease
• Malnutrition
• Obesity
• Ulcerative colitis

People who are older, are housebound, or have dark skin are also more vulnerable to vitamin D deficiency.

Vitamin D deficiency affects almost 50% of the population worldwide. Both vitamin D2 and D3 can be used to treat this, with vitamin D3 generally being the preferred choice.

Vitamin D3 vs. Vitamin D2

Vitamin D2 and vitamin D3 are chemically similar and are both well-absorbed in the gut. Where they differ significantly is in their sources:

• Vitamin D2 is naturally found in mushrooms, including shiitake, Portobello, and crimini mushrooms. The vitamin D content increases when these mushrooms are exposed to UV radiation.
• Vitamin D3 is naturally found in animals and animal-derived products like milk. It is also directly synthesized in the skin when it is exposed to ultraviolet B (UVB) radiation.

Aside from the fact that vitamin D3 is likely easier to consume in your day-to-day diet, unless you are a vegetarian or vegan, vitamin D3 has proven superior to vitamin D2 in two other important ways:

• Vitamin D3 has better bioavailability, meaning more of the vitamin enters the bloodstream and can be used by the body
• Vitamin D3 has a better half-life, meaning it stays in circulation for longer

Some studies suggest that vitamin D3 raises the vitamin D level in the bloodstream 87% more than vitamin D2.

On the downside, vitamin D3 in supplements has historically been synthesized using lanolin derived from sheep’s wool. This makes it unsuitable for those who choose to avoid animal-based products.

With that said, some manufacturers have been able to synthesize vitamin D3 from algae and lichen.

Vitamin D3 For Those Without Deficiency

Beyond its use in treating vitamin D deficiency, vitamin D3 may offer health benefits to certain people without such deficiency—in particular, those with high blood pressure or osteoporosis.

Hypertension

Hypertension, more commonly known as high blood pressure, is cardiovascular disease commonly seen in people with vitamin D deficiency.

Recent studies suggest that vitamin D3 may help lower blood pressure in people with hypertension and vitamin D deficiency as well as certain groups of people with hypertension only.

According to a 2019 review of studies in the journal Medicine involving 1,687 people, vitamin D3 was able to significantly reduce systolic (“top number”) blood pressure in people over the age of 50 and those with obesity.

This is important because isolated systolic hypertension can increase the risk of stroke, heart disease, and chronic kidney disease over time.

Osteoporosis

Osteoporosis is a frequent consequence of long-term vitamin D deficiency, so common wisdom would suggest that vitamin D supplements may help prevent or slow the progression of this common, aging-related bone disease. There is some evidence to support this claim.

A 2013 study from the University of Western Australia found that the use of vitamin D3 in nursing home residents aged 70 and over significantly reduced the incidence of hip fractures. In addition, low-dose vitamin D3 (400 IU) also increased bone mass density in the femoral (thigh) bone.

Unproven Benefits

Despite claims to the contrary, there is no evidence that vitamin D3 supplements can reduce the risk of cancer, coronary heart disease, or stroke. With that said, the supplements pose little, if any, harm if taken at the prescribed dose.

Sources of Vitamin D3

Whether you are nutritionally deficient or simply want to meet your recommended daily allowance (RDA) of vitamin D, you can obtain ample supplies of vitamin D3 from animal-based foods, dietary supplements, and sun exposure.

Dietary Sources

Food should always be the first source of vitamin D. Here are some of the best dietary sources of vitamin D3 to bolster your intake:

Some manufacturers of fruit juices, dairy products, margarine, and plant-based milk add vitamin D3 to boost their product’s nutritional value, as well.

Supplements

As convenient as they are, supplements should never be your primary source of vitamin D (or any nutrient, for that matter). They are really only intended for when you are not getting enough from your diet.

Vitamin D3 is readily available in supplement form and sold as capsules, softgels, gummies, and liquid drops. Most are formulated in doses higher than you need per day—between 2,000 and 10,000 IUs—but this is not a concern as only a portion will be absorbed. The rest will be passed in urine.

Talk to your healthcare provider about the best dose for you based on your age and medical history.

Sun Exposure

Vitamin D3 is unique in that (unlike vitamin D2) you can get it from the sun.

When exposed to UVB light, an organic compound in the skin called 7-dehydrocholesterol will activate and start churning out vitamin D3. The rate of production can vary by your age and skin tone, with older people and those with darker skin getting the least benefit.

Sunscreen can also decrease production by blocking both UV rays.

Getting a little sunlight every day can help you maintain your vitamin D levels, but it’s not the safest or most reliable way to get it given the risk of skin cancer.

Possible Risks

Vitamin D3 is generally regarded as safe, but it can on rare occasions cause toxic effects if you take too much. This is referred to as hypervitaminosis D.

With vitamin D toxicity, the balance of minerals like calcium and potassium is upset. This can lead to a condition known as hypercalcemia , in which too much calcium builds up in the body. This can lead to symptoms like:

• Stomach upset
• Nausea
• Vomiting
• Constipation
• Bone pain
• Muscle weakness
• An increased risk of bone fractures

Vitamin D toxicity was common in the 1940s when daily doses of 200,000 to 300,000 IUs per day were commonly recommended to treat chronic illnesses like tuberculosis and rheumatoid arthritis.

Today, vitamin D toxicity is considered a rare occurrence.

Recent studies have shown that vitamin D3 doses of 20,000 IUs per day are tolerable in adults with no signs of toxicity.

Summary

Vitamin D helps you absorb calcium and phosphate from food. It is important for bone and muscle strength and immune function, and it may have other benefits such as helping prevent inflammatory disease.

There are two types; vitamin D3 is more efficient in terms of how it can be used in the body than vitamin D2. You can get vitamin D from food or supplements, and your body can make D3 when exposed to sunshine.

Frequently Asked Questions

Vitamin D3 is a fat-soluble vitamin. This means that taking it with fat helps it absorb better. It doesn’t matter what time of day you take it, but you should eat fat-containing food when you do.

There are some at-home tests that can measure the amount of vitamin D in your blood. All you need to do is place a drop of blood on a test strip and mail it to the test’s manufacturer or designated lab for processing.

A lack of vitamin D can cause you to feel lethargic. Supplementing with D3 could, over time, help you feel more energetic, but only if you have a deficiency.

People with hyperparathyroidism, kidney disease, or hypercalcemia (high blood calcium) should typically avoid vitamin D3 supplements. Certain medications can also interact with vitamin D. Speak with your healthcare provider or pharmacist before starting any supplement.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

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• National Institutes of Health, Office of Dietary Supplements. Vitamin D fact sheet for consumers.

By Yvelette Stines
Yvelette Stines, MS, MEd, is an author, writer, and communications specialist specializing in health and wellness.