Vitamin D Supplements: How To Take Them Safely
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Please read this document in full before you decide whether to opt in and before you start taking the vitamin D supplements that have been provided to you.
Clinical Benefits Of Vitamin D
Vitamin D decreases cell proliferation and increases cell differentiation, stops the growth of new blood vessels, and has significant anti-inflammatory effects. Many studies have suggested a link between low vitamin D levels and an increased risk of cancer, with the strongest evidence for colorectal cancer. In the Health Professionals Follow-up Study , subjects with high vitamin D concentrations were half as likely to be diagnosed with colon cancer as those with low concentrations. A definitive conclusion cannot yet be made about the association between vitamin D concentration and cancer risk, but results from many studies are promising. There is some evidence linking higher vitamin D intake to a lower risk for breast cancer. The effect of menopausal status on this association is still unclear.
Several studies are providing evidence that the protective effect of vitamin D on the heart could be via the reninangiotensin hormone system, through the suppression of inflammation, or directly on the cells of the heart and blood-vessel walls. In the Framingham Heart Study, patients with low vitamin D concentrations had a 60% higher risk of heart disease than those with higher concentrations. In another study, which followed men and women for 4 years, patients with low vitamin D concentrations were three times more likely to be diagnosed with hypertension than those with high concentrations .
Type 2 diabetes
Dangers Of Too Much Vitamin D
Vitamin D toxicity is also referred to as vitamin D intoxication or hypervitaminosis D. The reason that taking too much vitamin D can be problematic is because vitamin D is a fat-soluble vitamin. This means its stored in body fat and can remain in your body for a long time.
Taking high doses of vitamin D causes your liver to produce a chemical called 25D, which makes calcium accumulate in your bloodstream . In rare cases this can result in kidney damage and calcium deposits forming in the kidneys . This is a serious condition that causes symptoms like nausea, dehydration, fever and pain.
25D can be measured via a blood test. A level of 25D int the blood that is higher than 150 ng/ml is considered potentially toxic.
While its rare, several other conditions aside from hypercalcemia can occur if someone experiences vitamin D toxicity, such as hyperparathyroidism, sarcoidosis and a few other rare diseases.
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Your Value Is Between 50
Congratulations, your values are in the optimum range to take advantage of the numerous health benefits of vitamin D. There is currently no sufficient scientific evidence to suggest that values above 60 ng/ml offer increased health benefits. Consequently, there is no need to attempt to reach higher levels.
Take the recommended dose of vitamin D daily to maintain your vitamin D levels, as described in point 1 above. Or continue to spend the same amount of time in the sun to maintain your value.
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.
Who Should Avoid Vitamin D
How much vitamin D is too much if you take other daily medications? Because vitamin D can interact with some medications, vitamin D supplements should not be taken by anyone who takes these prescription drugs:
- Epilepsy drugs, such as phenobarbital and phenytoin
- The weight loss medication called Orlistat
People who have any of the health conditions listed below should not supplement with vitamin D without being monitored by a doctor:
- Williams syndrome
How Much Is Too Much
Because high doses of some supplements can have risks, how do you know when it’s OK to take more than the RDA or DV?
One way is to look for the UL of a nutrient. With many vitamins and minerals, you can safely take a dose much higher than the RDA or DV without coming close to the UL.
For instance, the average person can take more than 50 times the RDA of vitamin B6 without reaching the upper limit. But some people develop symptoms of nerve pain with these higher levels of B6. So you should always be cautious. Here are some things to keep in mind:
Some supplements are riskier than others. With some vitamins and minerals, the upper limit is pretty close to the RDA. So it’s easy to get too much. For example, a man who takes just over three times the RDA of vitamin A would get more than the upper limit. High doses of vitamin A — and other fat-soluble vitamins like E and K — can build up in the body and become toxic. Other risky supplements include the minerals iron and selenium.
Supplementsare designed to be additions to your diet.Popping pills is not the answer to good health. Experts say you should eat a well-balanced diet and take supplements to fill in any nutritional gaps. Some people take a multivitamin with minerals for nutritional insurance.
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My Recommended Daily Dose For Vitamin D In Older Adults
For most older adults, I recommend a supplement of vitamin D 1000 IU/day.
I do this because:
- The American Geriatrics Society recommends that clinicians tell older patients to take vitamin D 1000 IU/day, to help prevent fractures.
I also do this because:
- Many older adults have risk factors for vitamin D deficiency. These include having osteoporosis and spending limited time outdoors.
- The skin becomes less able to synthesize vitamin D as people get older.
- Vitamin D seems to be involved in muscle function. Some research has suggested it can help reduce falls, other research hasnt confirmed this finding. Either way, it seems sensible to avoid frank deficiency.
- In the vast majority of older people, taking vitamin D 1000 IU as a supplement every day has very low risk of harm.
- Research suggests that taking vitamin D 1000 IU/day will prevent low vitamin D levels in most older adults.
Other expert groups have provided similar vitamin D guidance. For instance, in 2010 the Institute of Medicine published a report with age-based Recommended Daily Allowances for vitamin D in normal healthy persons. For people aged 1-70, they recommended 600 IU/day. For people aged 71+, they recommended 800 IU/day.
Research suggests that low levels of vitamin D are common in older adults who dont take supplements, but are uncommon in those who do take supplemental vitamin D.
Vitamin D Supplement Safety
Your body produces vitamin D when exposed to the sun, but many people may not get enough due to a variety of factors. Because of this, people often turn to vitamin D supplements. Unfortunately, it isnt uncommon for people to overdo it.
A 2017 study published in The Journal of the American Medical Association found that between 1999 and 2014, there was an increase in the number of American adults taking daily vitamin D supplements of 1,000 IU or more. Of these, 18% exceeded 1000 IU each day and 3% took more than 4,000 IU per day, which may place them at a higher risk of experiencing some adverse effects related to excessive vitamin D.
In most cases, you can get all of the vitamin D you need naturally without supplementation through sun exposure and diet. A 15-minute walk outside each day with your extremities exposed can boost vitamin D production. .
Eating foods that are naturally high in vitamin D or are fortified with the nutrient can help. Foods you can eat to boost your vitamin D levels include:
- Egg yolks
- Fortified milk, yogurt, or juice
- Fatter fish such as tuna or salmon
- Cod liver oil
If you do decide to take a vitamin D supplement to correct a deficiency or because you are unable to get an adequate amount through sunlight and diet, always follow your doctor’s guidelines and do not take more than recommended amounts.
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Where To Get Your Vitamin D
Vitamin D is called the sunshine vitamin since it is made in the skin after exposure to sun. The same UVB rays that cause a sunburn also make vitamin D. Sunscreen, darker skin pigmentation, clothing and reduced daylight in winter diminish the skins ability to make vitamin D. The people who experience the biggest seasonal swings in vitamin D levels are fair-skinned individuals living in the northern regions of the U.S. and at higher latitudes around the globe where there is very little daylight in winter.
But those most at risk for low vitamin D levels are people of color and people living at higher latitudes. Dark-skinned individuals are more likely than fair-skinned individuals to be low for vitamin D year-round because the darker skin blocks the UVB rays from producing vitamin D. However, even in dark skinned individuals, vitamin D is lowest in the winter.
In the winter, in addition to high vitamin D food, adults should take additional vitamin D from foods and/or supplements to get at least 600 IU per day of vitamin D. People who have dark skin or avoid sunshine should eat more vitamin D year-round.
Vitamin D Benefits And Warnings
Although the research is still hazy, some people will benefit from taking vitamin D supplements, along with sufficient calcium intake, to promote their bone health. But they don’t require large amounts of vitamin D to get the benefit. “More is not necessarily better. In fact, more can be worse,” says Dr. Manson. For example, a 2010 study published in JAMA showed that intake of very high doses of vitamin D in older women was associated with more falls and fractures.
In addition, taking a supplement that contains too much vitamin D can be toxic in rare cases. It can lead to hypercalcemia, a condition in which too much calcium builds up in the blood, potentially forming deposits in the arteries or soft tissues. It may also predispose women to painful kidney stones.
If you’re taking vitamin D supplements, the take-home message is moderation. Taking too much can limit the benefits of the sunshine vitamin.
Selected food sources of vitamin D
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Precautions Regarding Vitamin D Intake
If you notice signs of vitamin D side effects and youre at risk for experiencing vitamin D toxicity due to taking more than 300,000 IU in the past 24 hours or more than 10,000 IU per day for the past several months then stop taking vitamin D and visit your doctor right away for a blood test. Your doctor will test you for hypercalcemia and also discuss any symptoms youre having.
While taking too much vitamin D can be dangerous in some instances, keep in mind that getting too little vitamin D is also problematic. Your goal should be is to strike a balance and get the amount of vitamin D your body needs without taking excessive quantities.
Who Is Most At Risk Of Deficiency
Some people are at higher risk of vitamin D deficiency than others. For people at risk of vitamin D deficiency the government advises taking a vitamin D supplement all year round.
Those at higher risk of low vitamin D levels include:
People with dark skin
People with dark skin have more melanin, which reduces the skins ability to make vitamin D. Studies show people with dark skin generally have lower vitamin D levels.
People who cover their skin
We can only make vitamin D if our skin is exposed to the sun. People who cover most of their skin in the sun are unable to make vitamin D.
The government recommends that breast-fed babies are given a daily supplement containing vitamin D . This is because its hard to get enough from breast milk alone.
Even once a baby is weaned, its hard to get enough vitamin D from food and we tend to keep babies out of the sun, so theyre unlikely to get enough from sun exposure.
Formula milk is fortified with vitamin D, so babies having more than 500ml a day of formula shouldnt take a supplement.
People who rarely go outside
People who are frail, housebound or who live in a care home might not get out as much and as such have limited exposure to sunshine.
This also applies to people who work long days inside in shops or offices with little exposure to the sun.
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Biology Of The Sunshine Vitamin
Vitamin D is unique because it can be made in the skin from exposure to sunlight. Vitamin D exists in two forms. Vitamin D2 is obtained from the UV irradiation of the yeast sterol ergosterol and is found naturally in sun-exposed mushrooms. UVB light from the sun strikes the skin, and humans synthesize vitamin D3, so it is the most natural form. Human beings do not make vitamin D2, and most oil-rich fish such as salmon, mackerel, and herring contain vitamin D3. Vitamin D that is ingested is incorporated into chylomicrons, which are absorbed into the lymphatic system and enter the venous blood. Vitamin D that comes from the skin or diet is biologically inert and requires its first hydroxylation in the liver by the vitamin D-25-hydroxylase to 25D. However, 25D requires a further hydroxylation in the kidneys by the 25D-1-OHase to form the biologically active form of vitamin D 1,252D. 1,252D stimulates intestinal calcium absorption. Without vitamin D, only 1015% of dietary calcium and about 60% of phosphorus are absorbed. Vitamin D sufficiency enhances calcium and phosphorus absorption by 3040% and 80%, respectively.
Supplements : Vitamin D
Vitamin D is involved in many of your bodys functions. There are two forms in the diet, D2 and D3. It can also be produced in your skin when exposed to sunlight.
Vitamin D deficiency is a problem all over the world.
However, its pervasive in young women, infants, older adults, and people who have dark skin .
About 42% of the U.S. population is vitamin D deficient. However, this rate rises to 82% in Black people and 70% in Hispanics, which systemic problems likely play a role in .
If you have access to strong sun all year, then occasional sun exposure may be enough to fulfill your vitamin D requirements.
However, if you live far north or south of the equator, your vitamin D levels may fluctuate depending on the season. The levels may go down during the winter months due to a lack of sufficient sunlight .
In that case, you may need to rely on your diet for vitamin D as well as on vitamin D thats stored in body fat (
- intensify bone loss
- increase the risk of fractures
In children, a severe vitamin D deficiency can cause delays in growth and rickets, a disease where the bones become soft.
Furthermore, vitamin D deficiency is linked with several cancers, type 1 diabetes, multiple sclerosis, high blood pressure, and thyroid problems .
Vitamin D deficiency is prevalent worldwide but occurs at higher rates in specific populations. A deficiency in vitamin D is linked to various health problems.
How much vitamin D you need depends on many factors. These include:
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How Much Is Recommended Daily
If you do decide to take a supplement, it can get a bit confusing. Vitamin D doses can either be measured in international units or in micrograms and levels are very different. It’s easiest to stick to one – I’d recommend you look out for the number of micrograms. For reference, 10 mcg is equivalent to 400 IU.
Public Health England recommends that everyone over one year should take a supplement of 10 micrograms of vitamin D from around the end of September to early April. If you don’t get outside much, or if you cover up for religious reasons or have darker skin, you should take it all year round. It’s too early to tell if this new research will affect their recommendations.
Dr Louis Levy, Head of Nutrition Science at PHE, says: “A healthy, balanced diet and short bursts of sunshine will mean most people get all the vitamin D they need in spring and summer. However, everyone will need to consider taking a supplement in the autumn and winter if they don’t eat enough foods that naturally contain vitamin D or are fortified with it. And those who don’t get out in the sun or always cover their skin when they do, should take a vitamin D supplement throughout the year.”
Will Vitamin D Really Prevent Falls Or Fractures
Good question. Some studies have suggested that vitamin D reduces the chance of these serious health events, but these results have been questioned by later studies.
My current take is that vitamin D might help with falls and fracture risk, especially for certain older adults. Since it has a low chance of harm and possible helps some people a least a little, I recommend it.
However, I usually tell people to not have overly optimistic expectations of vitamin Ds effects. In most older adults, problems such as pain, fatigue, and/or falls are due to multiple underlying causes, so theres often no easy fix available.
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