Why Does Vitamin D Hang Around For So Long
Like vitamins A, E and K, vitamin D is fat-soluble and cannot dissolve in water.
Vitamins in this group are more easily absorbed by the body than water-soluble vitamins like C and B, particularly when taken with higher-fat foods.
Once they pass through the gut and bloodstream, fat- or oil-soluble vitamins are stored in fatty tissue.
This gives these types of vitamins a slower turnover than their water-soluble counterparts, said Treasure McGuire, a pharmacologist at The University of Queensland and Bond University.
“It’s the intracellular cumulation of oil-soluble vitamins thatcan become problematic with chronic misuse and overuse, even if people are thinking they’re doing it from a therapeutic standpoint,” said Dr McGuire, who was not involved in the study.
“It can take weeks or months for those levels to drop back in the tissue.”
While vitamin D toxicity is rare, studies have shown that it could become more common as more people rely on supplements as a boost.
A 2017 study on nearly 40,000 people in the US found that the number of people taking 1,000 IU or more of vitamin D had grown between 1999 and 2014.
About 18 per cent of the study participants took more than 1,000 IU of the vitamin each day, while another 3 per cent ingested over 4,000 IU daily.
And in 2019, an elderly woman in the UK died after taking 40,000 IU of vitamin D each day.
“We always have to make sure we recognise that what gets published is the tip of the iceberg.”
How Much Is Too Much
But while vitamin D supplements are generally safe, it’s possible to take too much.
According to the National Academy of Medicine in the US, the safe upper limit for vitamin D intake is 4,000 IU, or 100 micrograms, though higher doses may sometimes be used to treat health issues like deficiency, cardiovascular disease and diabetes over short periods.
Studies have shown that taking between 40,000 to 100,000 IU each day for several months can cause vitamin D toxicity.
This causes a build-up of calcium in the blood, a condition known as hypercalcemia, which leads to a wide variety of symptoms.
Some of these include nausea, vomiting, diarrhoea, fatigue, weight loss and excessive thirst.
Down the track, hypercalcemia can cause kidney problems, bone loss and hardening of the arteries and soft tissues.
When the man was admitted to hospital, he was suffering from vomiting and nausea.
At first, Dr Alkundi and his team initially thought the man had a bug and he was discharged the same day.
But he was back the following day with more severe symptoms like abdominal pain.
Blood tests showed the man’s vitamin D levels were seven times higher than normal and his calcium levels were sharply raised.
The tests also indicated that the man’s kidneys were failing to filter waste, a condition known as acute kidney injury or failure.
The man spent eight days in hospital, where he was flushed out with intravenous fluids.
“It took too long for him really,” he said.
How Much Vitamin D Should I Take For Specific Conditions
How much vitamin D should I take if Im deficient?
If a blood test has revealed that youre low in vitamin D, you can either take smaller doses for a long period of time to bring your level up, such as 5,000 to 10,000 IU per day, or a high dose administered over the course of several weeks. For adults with low vitamin D levels, the Endocrine Society recommends taking at least 1,5002,000 IU per day.
If youre taking a very high dose all at once, such as more than 40,000 IU, then its possible that side effects may occur due to vitamin D toxicity. The best thing to do is talk with your doctor about supplementing with higher doses of vitamin D if you are severely deficient or have a very low level according to a blood test.
How much vitamin D should I take for depression?
Theres some evidence that low vitamin D levels are linked with depression, although this doesnt mean that vitamin D deficiency causes depression. Rather, its speculated that people who dont spend much time outside or eat vitamin D foods may also be more likely to develop depression. The dosages of vitamin D used in studies that have focused on depression have varied, typically between 600 IU/day to 4,000 IU/day.
How much vitamin D should I take to lose weight?
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Vitamin D Supplements Vs The Sun
Even though you can get an active vitamin D metabolite from supplements, there may be a better source:
When UVB rays from the sun hit your skin they activate cholesterol which transforms it into vitamin D.
This process is so effective that in as little as 30 minutes your body can create the equivalent of 10,000 to 20,000 IUs of vitamin D in supplement form!
Getting vitamin D from the sun is not as easy as it sounds, though, because there are many factors that can reduce how effective sun exposure can be for vitamin D synthesis.
If you want to get vitamin D the all-natural way then you need to follow these instructions:
- Spend 10-20 minutes in the sun each day when the sun is directly over your head. If you go outside and the sun casts a shadow taller or longer than your body then the angle of the sun is not ideal.
- Expose at least 40% of your body to sunlight. This ensures enough surface area that the UVB rays can activate vitamin D in your skin.
- Avoid using sunscreen! Sunscreen will block UVB rays which means they wont help you create more vitamin D.
- Avoid going out in the sun if it is overcast. Clouds block UVB rays which means you wont create vitamin D.
The latitude at which you live also impacts how effective sun exposure is at creating vitamin D.
Can I Take Vitamin D3 Everyday
Most experts recommend that you shouldnt take more than 4,000 IU of vitamin D a day. When your serum D3 is very low , some may recommend a short course of once-weekly 50,000 IU of vitamin D2 or D3, followed by a usual dose of 600 to 800 IU daily.
Is it better to take vitamin D every day or once a week? Daily vitamin D was more effective than weekly, and monthly administration was the least effective.
How much vitamin D3 should a 50 year old woman take?
Adults aged up to 70 years old should be getting at least 600 IU. Adults older than 70 should be getting at least 800 IU of vitamin D.
Is 2000 IU of vitamin D safe? 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.
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Optimal Vitamin D Status
At the present time, 25D levels in the range of 30 to 60 ng/mL are considered optimal, but higher levels up to 100 ng/mL are often seen in individuals with outdoor occupations receiving intense sun exposure without ill effects.55 Correlative studies of 25D with muscle strength or risk of breast or colon cancer have prompted several investigators to suggest that the optimal 25OHD target for multiple health outcomes is 40 to 50 ng/mL.19,20 Garland et al23 suggest that increasing 25D to a range of 40 to 60 ng/mL from the current US average could reduce risk of breast cancer by 25% and colon cancer by 27%. Intakes of at least 4,000 IU daily from all sources would be needed to maintain 25D levels of 40 to 60 ng/mL. Practically speaking, supplements of 2,000 IU daily plus some sun exposure would probably be required to maintain a 25D level of 40 to 60 ng/mL year round.23
Symptoms Of Vitamin D Deficiency
It’s not easy to spot vitamin D deficiency. Some people might feel tired or get aches and pains.
But others may not have any symptoms until it’s too late, for example bowed legs or poor growth in children.
Your doctor can carry out a blood test to check your levels, but if you’re worried about your exposure to the sun or it’s winter you should start taking a supplement.
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Can We Get Enough Vitamin D From The Sun Alone
Although exposure to the sun is the most effective way to acquire adequate vitamin D, it comes with a cost. Furthermore, the quantity of sunlight required varies.
Individuals with darker skin, in particular those over the age of 60, produce less vitamin D in their skin.
Seasonality and geography are also important since vitamin D production varies with distance from the equator.
Vitamin D can also be formed in the skin through modest amounts of sun exposure, and it’s best to limit your time outdoors to 10 to 15 minutes, exposing your arms, legs, stomach, and back.
The Skin Cancer Organization says that you should only apply this product two to three times each week, followed by sunscreen. After then, your body will eliminate any extra vitamin D and you’ll be exposing yourself to sun damage with no added protection.
Keep in mind that the same thing that helps your body create vitamin D can also cause DNA damage, sunburn, and genetic mutations. This might lead to wrinkles appearing and raise your risk of skin cancer.
What Kind Of Vitamin D Supplement Should I Take
There are two different types of vitamin D. Vitamin D2 mainly comes from plant-based foods like UV grown mushrooms, or fortified foods and dietary supplements. Vitamin D3 comes from animals and supplements. Youll get D3 from fish oil, butter, liver, and egg yolks.
Vitamin D is available in supplemental form as a liquid, tablet, or capsule. Some doctors will even give vitamin D injections. D2 typically requires a prescription to get, and D3 is commonly available for purchase over-the-counter. There is some debate about whether D2 is stronger than D3 seeking medical advice is the best way to make sure you get the right form and dosage that you need.
The best form of vitamin D to take as a supplement is D3 although, D2 is acceptable, says Tod Cooperman, MD, founder of ConsumerLab. D3 is less likely to result in errors on blood tests, and high doses may raise levels better. In terms of formulations, liquids and pills are generally both fine . My preference is liquid drops, as you can easily adjust the dose. Plus, you can put it right on food or in a beverage, which should remind you that vitamin D, which is fat-soluble, should be taken with foods that contain fats to improve absorption.
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The Best Form Of Vitamin D For Hashimotos
There are two main forms that vitamin D supplements come in and one is definitely better than the other.
The two forms include:
When it comes to supplementing, vitamin D3 is the superior form.
Vitamin D2 tends to come from plant sources, is cheaper to produce, and may be of lesser quality compared to D3.
In addition, studies show that vitamin D3 is more potent at raising 25-hydroxy vitamin D levels compared to the D2 version.
This has to do with how your liver metabolizes D2 and D3.
The metabolism of D3 in the body results in more 25-hydroxyvitamin D3 than D2 even at equivalent doses.
When it comes to quality, D3 wins again.
Vitamin D2 is more susceptible to temperature changes and humidity which means that vitamin D2 supplements likely dont last as long as D3 supplements.
If you are taking a vitamin D supplement then check to make sure you are using the D3 formulation and not the D2 formulation.
Youll know if you are using the right formulation because the supplement fact panel on the back of your supplement will say cholecalciferol .
If your supplement fact panel says ergocalciferol then you are using the D2 formulation.
What Are Good Sources Of Vitamin D
You can get your vitamin D daily dosage from three main sources: the sun, food, and supplements. While you can spend 10-15 minutes in the sun without sunscreen every day to increase your vitamin D intake, you might be worried about damaging UV rays. Thats why its important to ensure your diet includes plenty of vitamin D-rich foods. Good sources include fatty fish, cod liver oils, beef liver, cheese, egg yolks, and mushrooms, as well as vitamin D-fortified foods . Finally, taking a vitamin D supplement can fill in any nutritional gaps.
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The Bottom Line
Vitamin D is important for maintaining bone health, muscle functioning, and immunity. But with up to 40% of U.S. adults having a vitamin D deficiency, you might be wondering, How much vitamin D should I take? The daily dosage depends on a variety of factors , but in general, its recommended that most adults take 15mcg or 600 IU of vitamin D per day.
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Learn More About Vitamins & Supplements:
This information is for educational purposes only and is not intended to serve as medical advice or a recommendation for any specific product. Consult your health care provider for more information.
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Your Value Is Between 80
These values are only slightly above those that can be achieved naturally by exposing the skin to the sunlight. It is assumed that these values cannot be achieved without taking vitamin D in dietary supplement form. To date, no risks are known which would result from consistently high values in the range of 80-100 ng/ml.
Getting Enough Vitamin D
In spring and summer, most people get enough vitamin D through sunlight on their skin and a healthy, balanced diet. During autumn and winter months, sunlight is not strong enough for the body to make vitamin D. People need to rely on dietary sources of vitamin D and consider taking a daily supplement.
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Other Important And Effective Ways To Protect Your Bones
There are other methods that may be more effective at maintaining bone health and reducing fracture risk. One that we can likely all agree on is regular physical activity. Weight-bearing exercise like walking, jogging, tennis, and aerobics definitely strengthens bones. Core exercises like yoga and Pilates can improve balance. All of this can help reduce falls and fracture risk.
And so, in the end, I am recommending what I always end up recommending: a Mediterranean-style diet rich in colorful plants, plenty of legumes, fish, plus low-sugar, low-fat dairy and plenty of varied physical activity throughout your entire life and maybe calcium and/or vitamin D supplementation for certain people, following a discussion with their doctors.
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Who Is Particularly At Risk Of Vitamin D Deficiency
Some people are at higher risk of vitamin D deficiency. If you are in one of these groups the NHS recommends you take a vitamin D supplement all year around.
Those at higher risk include:
- People with dark skin melanin reduces the skin’s ability to make vitamin D and people with dark skin have more melanin.
- People who cover their skin people who cover up when outside are unable to make enough vitamin D as their skin isn’t exposed to sunlight.
- People who stay indoors a lot people who are frail, housebound or live in a care home may not get enough exposure to sunlight.
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The Best Way To Test For Vitamin D Deficiency
There are several ways to assess your vitamin D status and each test has a different purpose.
When it comes to testing for vitamin D deficiency the best test is 25-hydroxyvitamin D .
The other vitamin D tests can be used to assess how well you are responding to treatment but should not be used to diagnose a deficiency.
These tests include:
- 1,25-dihydroxy vitamin D This is the active metabolite form of vitamin D but your body only converts a small percentage of your total vitamin D to this metabolite as necessary. As a result, 25-hydroxy vitamin D is still a better marker of overall vitamin D status.
- 25-hydroxy vitamin D2 This represents the amount of vitamin D2 your body has absorbed from plant sources.
- 25-hydroxy vitamin D3 This is the amount of vitamin D3 your body has absorbed from animal sources or from supplements.
The 25-hydroxy vitamin D2 and D3 metabolites may be helpful in cases where you are taking supplements and not seeing an increase in your 25-hydroxy vitamin D status.
They are typically not recommended for monitoring, though, and are really only used in specific cases.
The test you want to get before you supplement is 25-hydroxy vitamin D.
Advice For Adults And Children Over 4 Years Old
During the autumn and winter, you need to get vitamin D from your diet because the sun is not strong enough for the body to make vitamin D.
But since it’s difficult for people to get enough vitamin D from food alone, everyone should consider taking a daily supplement containing 10 micrograms of vitamin D during the autumn and winter.
Between late March/early April to the end of September, most people can make all the vitamin D they need through sunlight on their skin and from a balanced diet.
You may choose not to take a vitamin D supplement during these months.
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