Vitamin D supplements: are they really good for our health? (2023)

There is no doubt that our bodies need vitamin D. It helps regulate the absorption of calcium and phosphorus in our bones, helps our cells to communicate with each other, and helps strengthen our immune system. But can vitamin D supplementation really offer additional health benefits?

Previous research suggests it can. But other studies indicate that vitamin D supplementation does not do any more than promote bone and immune system health and is only useful for people who have a vitamin D deficiency.

We look at both sides of the argument in an attempt to determine whether vitamin D supplementation really is good for us.

Vitamin D is a fat-soluble vitamin. There are five forms of the vitamin – D1, D2, D3, D4 and D5.

However, vitamins D2 and D3 appear to be the most important in the human body.

Sunlight is the the body’s main source of vitamin D. There is no set amount of time a person should spend in the sunlight to get a good amount of this vitamin. However, the Vitamin D Council state that “you don’t need to tan or burn your skin to get vitamin D.”

The UK’s National Health Service (NHS) states that short bursts of sun exposure during summer months should be enough.

The energy from the sun changes a chemical in the skin to vitamin D3, which is then carried to the liver and the kidneys where it is made into active vitamin D.

Some foods, such as oily fish, eggs and fortified fat spreads, also contain the vitamin, although these are in very small amounts. Once consumed, it is sent to the liver and processed in the same way.

The main function of vitamin D is to increase the intestinal absorption of calcium – a process that is crucial for good bone health.

Vitamin D also helps strengthen the immune system and aids cell to cell communication in the body.

The Vitamin D Council also state that the vitamin is important for muscle function, the respiratory system, cardiovascular function, brain development, and it even has anti-cancer properties.

(Video) Are Vitamin D Supplements Safe?

Vitamin D deficiency occurs when a person does not have the sufficient amount of the vitamin in their body.

According to the Food and Nutrition Board at the Institute of Medicine of The National Academies, the recommended dietary allowance of vitamin D for people aged 1-70 is 600 IU each day and 800 IU for those aged over 70 years.

Infants between 0-12 months should have an intake of 400 IU of vitamin D each day.

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The NHS state that the majority of people should be able to get all the vitamin D the body needs by eating a healthy balanced diet and getting the right amount of sunlight.

But certain groups may be at risk of vitamin D deficiency. These include:

  • People aged 65 and over
  • Pregnant and breastfeeding women
  • Individuals who are not exposed to enough sunlight, such as people who are housebound
  • People who have darker skin, and
  • Babies and young children under the age of 5.

According to Harvard Medical School, if the body does not get enough vitamin D, it can only absorb 10-15% of dietary calcium, compared with 30-40% with sufficient vitamin D levels.

This can have negative impacts on bone health. Last year, Medical News Today reported on a study revealing that vitamin D deficiency may speed up the aging of bones.

Low vitamin D levels have also been linked to other negative health effects. A recent study suggested that vitamin D deficiency may cause damage to the brain.

Research has also revealed potential implications for vitamin D deficiency during pregnancy. A study recently suggesting that women who have low vitamin D levels in the first 26 weeks of gestation may have an increased risk of preeclampsia.

According to the Vitamin D Council, symptoms of vitamin D deficiency can include tiredness and general aches and pains, but many people do not have any symptoms.

The Vitamin D Council state that the two main ways to get sufficient amounts of vitamin D in the body are to expose bare skin to sunlight and take vitamin D supplements.

But Brant Cebulla, development director of the Vitamin D Council, told Medical News Today that for many people, frequent exposure to sunlight is not possible:

With our indoor lifestyles, we don’t expose skin to the sun as much as we used to and are not fulfilling our vitamin D requirements. Supplements are one way to make up for this lifestyle.”

Vitamin D supplementation has been linked to numerous health benefits.

Last year, Medical News Today reported on a study suggesting that vitamin D supplements may reduce pain and depression for women with type 2 diabetes.

More recent research has suggested that high levels of vitamin D may prevent cognitive impairment in patients with Parkinson’s disease, while another study found that high vitamin D intake during pregnancy may increase the muscle strength of offspring.

(Video) Supplements: The health benefits of vitamin D

However, some studies have questioned the potential health benefits of vitamin D supplementation.

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Last year, a study published in The Lancet Diabetes & Endocrinology that analyzed 290 prospective observational studies and 172 randomized trials of vitamin D supplements, found no evidence that vitamin D supplementation yields any health benefits.

Furthermore, the study researchers suggested that low vitamin D levels are a consequence of ill health, not a cause.

(Video) Put down the Vitamin D supplements - you could be ruining your health! Jim Stephenson Jr.

A more recent study, also published in The Lancet Diabetes & Endocrinology questioned the health benefits of vitamin D supplementation.

The research team, led by Dr. Mark Bolland of the University of Auckland in New Zealand, found that vitamin D supplementation is unlikely to reduce the incidence of heart attack, heart disease, stroke, cancer or bone fractures.

Talking to Medical News Today, Dr. Bolland said of the team’s findings:

The main message is that if you are otherwise healthy and active, you are likely to receive enough sunshine to have adequate vitamin D levels and don’t need to take vitamin D supplements.”

However, Cebulla noted that studies such as these may not be showing the true effects of vitamin D supplementation:

“These meta-analyses pulled lots of data from trials that used really low amounts of vitamin D (400 or 800 IU a day), so it’s hard to expect results that show any benefits.”

He added that future studies should provide more accurate results:

“We’ve got better designed large trials underway now, using 2,000 IU of vitamin D a day or more, and results from those will be out in 2017-2020. One such trial is VITAL, which is enrolling 20,000 Americans to take either 2,000 IU of vitamin D or placebo for 5 years. We should get really good data from that, data that doesn’t exist to date.”

Like many other vitamins, excess intake of vitamin D can pose negative health effects.

According to the University of Maryland Medical Center, side effects can include poor appetite, weight loss, tiredness, sore eyes, vomiting, diarrhea and muscle problems.

“If you have extremely high levels of vitamin D, you could get a condition called hypercalcemia, which means too much calcium in your blood,” added Cebulla.

“This condition makes you feel nauseous, confused and tired. If you get medical attention and lower your vitamin D intake and lower your calcium levels, there are no long lasting effects.”

(Video) Do You Need Vitamin D Supplements?

The University of Maryland Medical Center states that it is hard to get too much vitamin D from sunlight and food sources, therefore excess vitamin D intake is generally a result of taking too many supplements.

However, it is difficult to say how much is too much because most organizations recommend different maximum intakes of vitamin D.

For example, the Food and Nutrition Board recommend that 4,000 IU is the maximum amount of vitamin D that should be taken each day, while the Vitamin D Council recommend 10,000 IU as the maximum.

However, the Vitamin D Council note:

“While these amounts seem like a lot, keep in mind that your body can produce 10,000 to 25,000 IUs of vitamin D after a little bit of full body sun exposure. Vitamin D toxicity, where vitamin D can be harmful, usually happens if you take 40,000 IU a day for a couple of months or longer.”

Cebulla told Medical News Today that in order to ensure individuals are getting the right amounts of vitamin D, doctors should be discussing vitamin D intake with their patients:

Studies show that traditional dietary counseling do not improve vitamin D intake/levels. So it’s important for doctors to make sure they communicate that vitamin D isn’t something that comes from your diet, and extra attention is needed to make sure you’re getting enough vitamin D.”

Furthermore, Cebulla added that increased awareness surrounding vitamin D would lead to better vitamin D intake over the population.

“We need a population that understands you get vitamin D from sun exposure, and if you’re not getting sun exposure, then you need to supplement because you’re not getting enough vitamin D from your diet,” he said.

For now, evidence suggests that vitamin D supplements may help to maintain the levels of the vitamin our bodies need to promote bone health, modulation of cell growth and immune function.

But whether these supplements can promote additional health benefits remains to be seen.


Are vitamin D supplements really useful? ›

So it's perhaps natural to assume that vitamin D supplements may help strengthen our bones and protect against fractures and falls. But a large review of the research, published in October, concluded that vitamin D supplements, in low or high doses, play no such role.

Should I take a vitamin D supplement daily? ›

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, as it is not linked to any extra health benefits.

What are the signs you need vitamin D? ›

Symptoms when vitamin D is low
  • Fatigue.
  • Not sleeping well.
  • Bone pain or achiness.
  • Depression or feelings of sadness.
  • Hair loss.
  • Muscle weakness.
  • Loss of appetite.
  • Getting sick more easily.
19 Jul 2022

Is it better to get vitamin D from the sun or supplements? ›

Vitamin D is made in the skin when it's exposed to sunlight. Sun exposure is by far the best way to boost vitamin D levels, particularly because very few foods contain significant amounts.

When should I take vitamin D morning or night? ›

While the best timing has not been established, scientific data to confirm anecdotal reports that supplementing at night may interfere with sleep is unavailable. Current research suggests you can fit vitamin D into your routine whenever you prefer.

What foods have lots of vitamin D? ›

Food Sources
  • Cod liver oil.
  • Salmon.
  • Swordfish.
  • Tuna fish.
  • Orange juice fortified with vitamin D.
  • Dairy and plant milks fortified with vitamin D.
  • Sardines.
  • Beef liver.

What is the safest amount of vitamin D to take daily? ›

Mayo Clinic recommends that adults get at least the RDA of 600 IU. However, 1,000 to 2,000 IU per day of vitamin D from a supplement is generally safe, should help people achieve an adequate blood level of vitamin D, and may have additional health benefits.

What are the five signs you may have vitamin D deficiency? ›

Here are five signs to watch out for:
  • Fatigue. Feeling fatigued and sluggish is probably the most common sign of vitamin D deficiency, Dr. ...
  • Broken Bones and Stress Fractures. “Bone fractures that don't heal quickly are another sign [of vitamin D deficiency],” Gittleman says. ...
  • Low Immunity. ...
  • Muscle Pain and Achiness. ...
  • Hair Loss.
7 Jun 2021

What will happen if vitamin D is low? ›

Vitamin D deficiency can lead to a loss of bone density, which can contribute to osteoporosis and fractures (broken bones). Severe vitamin D deficiency can also lead to other diseases. In children, it can cause rickets. Rickets is a rare disease that causes the bones to become soft and bend.

What happens when your body is low on vitamin D? ›

Left untreated, vitamin D deficiency can lead to osteoporosis in adults, rickets in children and adverse outcomes in pregnant women. It may also be linked to heart disease, diabetes and cancer — although more study is needed on the topic.

Is oral vitamin D as good as sun? ›

Both sun exposure and oral vitamin D3 were effective in improving serum 25OHD levels. Compared with placebo, the between-group LSM differences in changes (95% CIs) were 2.2 ng/mL (0.2, 4.2) for sun exposure and 8.5 ng/mL (6.5, 10.5) for oral vitamin D3.

How long does it take vitamin D to work? ›

How Long Does It Take for Vitamin D to Work? If you have a vitamin D deficiency, you may notice improvements within 4-6 weeks of consistent supplementation. However, that timeframe can vary depending on what your baseline vitamin D levels are.

Which is more important vitamin D or calcium? ›

Calcium and vitamin D work together to protect your bones—calcium helps build and maintain bones, while vitamin D helps your body effectively absorb calcium. So even if you're taking in enough calcium, it could be going to waste if you're deficient in vitamin D.

Why should you not take vitamin D at night? ›

Vitamin D and sleep: The surprising connection

Early research suggests it is inversely related to melatonin, your sleep hormone. Increasing vitamin D levels may suppress melatonin levels. So, it makes sense that taking it at night could disrupt your sleep.

Does vitamin D Help sleep? ›

Growing evidence has demonstrated that vitamin D has a role in sleep regulation [12]. Specifically, vitamin D deficiency (VDD) can increase risk of sleep disorders and is associated with sleep difficulties, shorter sleep duration, and nocturnal awakenings in children and adults [13,14,15].

What time of day is vitamin D strongest? ›

To get an optimal vitamin D supplement from the sun at a minimal risk of getting cutaneous malignant melanoma (CMM), the best time of sun exposure is noon.

Which vegetable is high in vitamin D? ›


Other than fortified foods, mushrooms are the only sufficient non-animal source of vitamin D. Like humans, mushrooms can synthesize vitamin D when exposed to UV light ( 22 ).

Do bananas have vitamin D? ›

Nope, no vitamin D here. But bananas do contain plenty of magnesium. And guess what? Among the many reasons you need magnesium is that once your vitamin D is in your bloodstream, the magnesium puts it to work, making magnesium a must-have in order for you to access the many benefits of vitamin D.

What is the best way to get vitamin D naturally? ›

  1. Spend time in sunlight. Vitamin D is often referred to as “the sunshine vitamin” because the sun is one of the best sources of this nutrient. ...
  2. Consume fatty fish and seafood. ...
  3. Eat more mushrooms. ...
  4. Include egg yolks in your diet. ...
  5. Eat fortified foods. ...
  6. Take a supplement. ...
  7. Try a UV lamp.
17 Mar 2019

What is the differences between vitamin D and D3? ›

There are quite a few differences between vitamin D and vitamin D3, but the main difference between them is that vitamin D is a fat-soluble vitamin that regulates calcium and phosphorous levels in the body, whereas the vitamin D3 is the natural form of vitamin D produced by the body from sunlight.

Is vitamin D3 and vitamin D the same? ›

What's the difference between vitamin D and vitamin D3? There are two possible forms of vitamin D in the human body: vitamin D2 and vitamin D3. Both D2 and D3 are simply called “vitamin D,” so there's no meaningful difference between vitamin D3 and just vitamin D.

How long do vitamin D supplements stay in your body? ›

Vitamin D undergoes two hydroxylations in the body for activation. Calcitriol (1,25-dihydroxyvitamin D3), the active form of vitamin D, has a half-life of about 15 h, while calcidiol (25-hydroxyvitamin D3) has a half-life of about 15 days.

Why is vitamin D hype so impervious to evidence? ›

One major reason for the failure of persuasion of evidence is spin—or language that distracts from the primary endpoint. Here are two (of many) examples: A meta-analysis of 50 vitamin D trials set out to study mortality. The authors found no significant difference in that primary endpoint.

Which form of vitamin D is best absorbed? ›

In our study, the microencapsulated form of vitamin D was the most bioavailable.

What is the best form of vitamin D to take? ›

Choosing the Best Vitamin D Supplement for Your Health

If you choose to go the supplement route, Clifford recommends taking around 400 to 800 IU of vitamin D3 (cholecalciferol) per day. “Vitamin D3 is the form that is already stored in the body, so some studies have found it to be more effective,” Clifford says.

What is the problem with vitamin D? ›

The main consequence of vitamin D toxicity is a buildup of calcium in your blood (hypercalcemia), which can cause nausea and vomiting, weakness, and frequent urination. Vitamin D toxicity might progress to bone pain and kidney problems, such as the formation of calcium stones.

Are vitamin D supplements a waste of money? ›

That paper concluded that vitamin D supplements do not improve bone density, and they do not reduce the risk of osteoporosis. In other words, vitamin D supplements are a complete waste of money.

Can vitamin D cause memory issues? ›

Vitamin D deficiency, or even just less-than-optimal levels of the sunshine vitamin, can spell trouble for your memory and moods.

What are the negatives of vitamin D3? ›

Is too much vitamin D3 (cholecalciferol) harmful? Yes, having vitamin D levels that are too high in your body can lead to high blood levels of calcium. This can be harmful to your kidneys and cause side effects, such as nausea, constipation, loss of appetite, muscle weakness, and kidney stones.

Is vitamin D best taken in the morning or night? ›

While the best timing has not been established, scientific data to confirm anecdotal reports that supplementing at night may interfere with sleep is unavailable. Current research suggests you can fit vitamin D into your routine whenever you prefer.

Does D3 affect blood pressure? ›

Conclusion: Oral vitamin D 3 has no significant effect on blood pressure in people with vitamin D deficiency. It reduces systolic blood pressure in people with vitamin D deficiency that was older than 50 years old or obese.

Which fruit is rich in vitamin D? ›

Top 8 Vitamin D Fruits, Vegetables And Foods You Need To Know About
  • Orange juice.
  • Eggs.
  • Salmon.
  • Milk.
  • Tofu.
  • Mushrooms.
  • Cod liver oil.
  • Raw Oysters.
14 Feb 2020

What blocks vitamin D from being absorbed? ›

Because vitamin D is fat soluble, its absorption depends on the gut's ability to absorb dietary fat [4]. Fat malabsorption is associated with medical conditions that include some forms of liver disease, cystic fibrosis, celiac disease, Crohn's disease, and ulcerative colitis [1,63].

Is there a difference between vitamin D and D3? ›

There are quite a few differences between vitamin D and vitamin D3, but the main difference between them is that vitamin D is a fat-soluble vitamin that regulates calcium and phosphorous levels in the body, whereas the vitamin D3 is the natural form of vitamin D produced by the body from sunlight.

How long does it take for vitamin D to work? ›

“Adding an over-the-counter vitamin D supplement can make improvements in just three to four months time. Vitamin D with a strength of 1000-2000 international units daily is the recommended dose for most adults,” Dr. Ropte says. Most multivitamins contain vitamin D, so extra supplementation isn't always necessary.


1. Vitamin D Supplements Continue to Be Unnecessary
(Healthcare Triage)
2. How Much Vitamin D Do I Need? SURPRISING
(Dr. Eric Berg DC)
3. How to Know the Best VITAMIN D Supplement to Buy! Dr. Mandell
4. Vitamin D warning: take supplements or risk your health
(5 News)
5. Study shows Vitamin D has many benefits
(WBAL-TV 11 Baltimore)
6. Most People Don't Need Vitamin D Supplements
(Healthcare Triage)
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