Two Types Of Vitamin D
There are two basic types of vitamin D used in supplements.
Vitamin D2 is the form of vitamin D synthesized by plants, not animals. Its generally obtained from irradiated mushrooms for use in supplements. Youll often find less expensive vitamin D supplements containing the D2 form.
Vitamin D3 is the form of the vitamin your body naturally produces when exposed to sunshine. Vitamin D3 is generally obtained from lambs wool for use in supplements. While studies have shown that both D2 and D3 can raise blood levels of vitamin D to healthy levels, they have also shown that D3 does a far better jobmaintaining those levels than D2. For this reason, most nutritionists and other health experts recommend taking a vitamin D supplement containing D3.
What Is The Relationship Between Vitamin D And Sun Exposure
It is well established that sunshine is a significant source of vitamin D as UVB rays from sunlight trigger vitamin D3 manufacture in the skin. However, there is little information available about how much sunlight is necessary to make enough vitamin D3 to maintain adequate serum calcitriol levels to form and maintain healthy, strong bones. On the other hand, there is much evidence around about the dangers of over exposure to sunlight and its role in causing skin cancer. There has been much discussion about how to achieve a balance between exposing oneself to enough sunlight to maintain adequate vitamin D levels and avoiding an increase in the risk of skin cancer.
What Causes Vitamin D Deficiency
Vitamin D deficiency can be caused by specific medical conditions, such as:
- Cystic fibrosis, Crohn’s disease, and celiac disease: These diseases do not allow the intestines to absorb enough vitamin D through supplements.
- Weight loss surgeries. Weight loss surgeries that reduce the size of the stomach and/or bypasses part of the small intestines make it very difficult to consume sufficient quantities of certain nutrients, vitamins, and minerals. These individuals need to be carefully monitored by their doctors and need to continue to take vitamin D and other supplements throughout their lives.
- Obesity: A body mass index greater than 30 is associated with lower vitamin D levels. Fat cells keep vitamin D isolated so that it is not released. Vitamin D deficiency is more likely in obese people. Obesity often makes it necessary to take larger doses of vitamin D supplements in order to reach and maintain normal D levels.
- Kidney and liver diseases: These diseases reduce the amount of an enzyme needed to change vitamin D to a form that is used in the body. Lack of this enzyme leads to an inadequate level of active vitamin D in the body.
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Vitamin D Can Help Prevent Type 1 And Type 2 Diabetes
While studies are not conclusive, vitamin D may be helpful for preventing both type 1 and type 2 diabetes, says Newgent. One such study, published in 2006 in the journal Diabetes Care, found that while vitamin D on its own did not effectively lower the risk of an overabundance of sugar in the blood, a combined daily intake of > 1,200 mg calcium and > 800 IU vitamin D could effectively lower the risk of type 2 diabetes.
Help Prevent Cognitive Decline And Dementia
Foroutan points out that there are vitamin D receptors in brain tissue, which suggests that the vitamin may play a role in cognitive function and, potentially, the risk of dementia. Research may support this notion, with one article suggesting that vitamin D may help clear up amyloid plaque, the hallmark of Alzheimers disease . The authors note that more research is needed to confirm a cause-and-effect relationship between an adequate level of vitamin D and the neurodegenerative disorder.
Meanwhile, a large review published in July 2018 in Nutritional Neuroscience found insufficient evidence that vitamin D supplements protect against neurodegenerative diseases such as Alzheimers and Parkinsons disease. Researchers wrote that they also couldnt confirm that vitamin D synthesized from sun exposure helps to protect against neurodegenerative diseases.
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What Does Your Diet Have To Do With Getting Enough Vitamin D
Vitamin D doesnt occur naturally in many foods. Thats why certain foods have added vitamin D. In fact, newer food nutrition labels show the amount of vitamin D contained in a particular food item.
It may be difficult, especially for vegans or people who are lactose-intolerant, to get enough vitamin D from their diets, which is why some people may choose to take supplements. It is always important to eat a variety of healthy foods from all food groups. The vitamin content of various foods is shown in the following table.
Vitamin D content of various foods
|Cheese, Swiss, 1 ounce
It is important to check product labels, as the amount of added vitamin D varies when it is artificially added to products such as orange juice, yogurt and margarine.
Vitamin D Can Help Strengthen Oral Health
Because vitamin D helps our body absorb calcium, it plays a crucial role in supporting oral health, lowering the risk of tooth decay and gum disease. A 2011 review in The Journal of the Tennessee Dental Association notes that while the research is scant, there’s an “emerging hypothesis” that the vitamin is beneficial for oral health, due to its effect on bone metabolism and “its ability to function as an anti-inflammatory agent and stimulate the production of anti-microbial peptides.”
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Why Is Vitamin D Important
Vitamin D is important for the absorption of calcium from your stomach and for the functioning of calcium in your body. This helps your bones to stay healthy and your muscles to work well.
- Low levels of vitamin D are linked to bone conditions such as rickets in children and osteoporosis and osteomalacia in adults.
- Low vitamin D levels may also be linked to non-skeletal health conditions, such as colorectal cancer,cardiovascular disease and immune system problems. Researchers are looking into whether increasing vitamin D levels could help prevent any of these conditions, but the evidence is not clear at this stage.
- Vitamin D has been shown to help reduce falls and fractures in older people in residential care. More research is needed to see if vitamin D could help reduce falls and fractures in other groups of people.
- However, too much vitamin D replacement can lead to high levels, which can actually increase your risk of falls. For this reason, you should only take vitamin D as recommended and prescribed by a doctor.
What Is The Link Between Vitamin D And Winter Health
Vitamin D is sometimes called the sunshine vitamin because your body produces it in response to sunlight. In winter we get less sun and more flu. Researchers have been looking into whether the two might be related. Some studies have found signs of people with lower vitamin D levels being more likely to get colds and flu, but more research is needed.
However, if you have low levels of vitamins D, you may be walking around with a weakened immune system, which can leave you susceptible to viral infections, like colds and the flu.
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Dietary Sources And Intake Data
Vitamin D2 and D3 are fat-soluble. The major food sources for naturally occurring vitamin D3 include animal foods such as fatty fish, offal , meat and meat products, and egg yolks .
Fish have the highest natural content of vitamin D , presumably derived from an accumulation in the food chain originating from microalgae that contain both vitamin D3 and provitamin D3 . Egg yolk also has a high vitamin D3 content , which strongly correlates with the content of vitamin D3 of the hen’s feed . Animal studies showed that vitamin D3 and 25D3 were effectively transferred from the hen to the egg yolk, depending on the hen’s diet and UV-B exposure . The content of vitamin D of meat products varies and depends, among other things, on the contents of vitamin D in the fodder, the fat content of the meat product, and latitude where the animals have grazed .
The vitamin D metabolite 25D is present in some foods of animal origin in varying amounts . Due to the suggested higher biological activity of 25D in foods compared with the native vitamin D, a conversion factor of 5 has been used for 25D3 in the calculation of total vitamin D3 in some food composition tables, including those in the UK, Denmark and Switzerland .
Some higher fungi, such as mushrooms, are a natural source of vitamin D2. Vitamin D2 is produced in fungi and yeasts by UV-B exposure of provitamin D2 and the content depends on the amount of UV-B light exposure and time of exposure .
Dealing With Missing Data
The contractor contacted the original authors of the individual studies to obtain relevant missing data imputation was used in the current analysis to deal with key summary information that could not be retrieved despite the contractor’s efforts.
Specific formulae were applied to derive summary data where not directly extracted/available in the format of the statistics mentioned in Section of this Appendix . If no calculation/estimation was possible, the missing data were imputed according to the approach proposed by Wan et al. .
Information for all relevant study-level characteristics was complete with the exceptions of funding source , ethnicity and mean Body Mass Index . Availability of BMI mean values in the final data set was maximised by calculating it from mean weight and mean height /height2 ) when available missing data proportion dropped to 16%. While developing the final model, BMI missing data were included in a specific category as not reported, to be able to compare models with and without BMI as covariate . Funding and ethnicity were analysed likewise, although the high proportion of missing values for ethnicity prevented it from being included in the final model.
Only for one trial on children from Mongolia values were imputed from another included trial on children from Denmark, as participants were of comparable age.
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Vitamin D Can Help Battle Depression
The sun can brighten up your mood, and so can vitamin D. According to a 2017 review article in the journal Neuropsychology, researchers found “a significant relationship between depression and vitamin D deficiency. While they acknowledged that more research is needed to define the exact workings of itsuch as, if low vitamin D levels are a cause or effect of depressionthe authors recommend screening for and treating vitamin D deficiency in subjects with depression noting that it is an easy, cost-effective and may improve depression outcome.
Uv Levels In Victoria
As shown in the table below, from mid-August to April, average UV levels in Victoria are three and above for much of the day. This level of UV increases the risk of overexposure and skin damage, and sun protection is recommended. Using good sun protection should not put people at risk of vitamin D deficiency.From May to mid-August, average UV levels in Victoria are low . During this time, sun protection is not recommended, unless you work outdoors, are near highly reflective surfaces , or are outside for extended periods.
Can You Get Too Much Vitamin D
Too much vitamin D can cause toxicity that results in nausea, vomiting, poor appetite, constipation, weakness and weight loss. It can also raise blood calcium levels, causing mental status changes such as confusion and heart rhythm abnormalities.
Sun exposure is unlikely to result in vitamin D toxicity. Other compounds produced in the skin protect the body from synthesising too much vitamin D during periods of prolonged sun exposure. Vitamin D toxicity is likely to occur from overdose of vitamin D supplements. People taking vitamin D supplements should never exceed the recommended dose and should be made aware of the side effects of vitamin D overdose.
Three Surprising Vitamin D Benefits For Men
There are a number of vitamin D benefits for men. Lately,vitamin Dhas been the subject of much clinical study. Research shows that vitamin D is not just important forbone health.This vital nutrient also plays a role in supporting healthy muscle development, testosterone levels, and mental health. In this article, we provide information about vitamin D and share three surprising vitamin D benefits for men.
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What Are The Signs And Symptoms Of Vitamin D Deficiency
Severe lack of vitamin D causes rickets, which shows up in children as incorrect growth patterns, weakness in muscles, pain in bones and deformities in joints. This is very rare. However, children who are deficient in vitamin D can also have muscle weakness or sore and painful muscles.
Lack of vitamin D is not quite as obvious in adults. Signs and symptoms might include:
Some Perspective On What Is And Isnt Vitamin D Deficiency
I spoke with osteoporosis expert Dr. Joel Finkelstein, associate director of the Bone Density Center at Massachusetts General Hospital, whose research in this field spans over three decades. He agreed with the authors of the NEJM article that we are currently over-screening for vitamin D deficiency, and overtreating people who are getting enough vitamin D through diet and sun exposure. “Vitamin D has been hyped massively,” he states. “We do not need to be checking the vitamin D levels of most healthy individuals.”
He points out that from an evolutionary standpoint, it doesnt make sense that higher vitamin D levels would be beneficial to humans. “Vitamin D is actually quite hard to find in naturally occurring food sources,” he points out. “Yes, we can get vitamin D from the sun, but our bodies evolved to create darker skin in the parts of the world that get the most sun. If vitamin D is so critical to humans, why would we evolve in this way, to require something that is hard to come by, and then evolve in such a way as to make it harder to absorb?”
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Vitamin D Can Support The Immune System And Fight Inflammation
Dr. Nasrallah adds that vitamin D can also help build immunity. It can support the immune system by fighting off harmful bacteria and viruses, she says. In fact, this role in possibly preventing infections has become a critical concern during COVID-19 pandemic, as researchers are interested in its potential role in infection outcomes. There is particular interest in its role in viral infections such as influenza and coronavirus,Barry Boyd, MD, RDN, a Yale Medicine hematologist, oncologist, and nutritionist, tells Health. He points to a 2017 BMJ analysis of 25 randomized control trials comparing vitamin D supplements to placebos, which found that vitamin D reduced the risk of acute respiratory infection with either daily or weekly vitamin D supplementation, particularly in individuals who were deficient in it. Studies indicate that high latitudes and winter season are risk factors for both low vitamin D, increased influenza, and other respiratory illness and adverse outcomes, he says. We now are seeing a similar pattern with higher mortality rates in COVID-19 infections,” though more research still needs to be done to determine whether the link is causal or merely a correlation.
Vitamin D Deficiency And Its Consequences
In past decades, studies have found 12.5% to 76% of osteoporotic postmenopausal women with vitamin D values below 12 ng/ml, with regional and seasonal variations and this deficiency is accentuated in direct proportion to the age of studied group, influencing negatively to bone metabolism . In states of vitamin D deficiency, decreased calcium absorption in the intestine causes secondary hyperparathyroidism, resulting in bone loss. In addition, loss of renal phosphate alters the calcium-phosphate products causing reduced mineralization of bone matrix, the latter effect can result in rickets in children and osteomalacia in adults. Vitamin D, by increasing calcium absorption, prevents hyperparathyroidism and benefits the development of optimal bone mass and proper bone matrix mineralization. Both factors are responsible for optimizing the mechanical strength of bone . In children, an adequate consumption of vitamin D is related to an increased gain of bone mass in proper conditions of calcium ingestion . This is important because in late adolescence, 25-50% of the peak bone mass is reached during this period so deficient ingestion of calcium and vitamin D has deleterious effects on the peak bone mass that will be reached in adulthood. Vitamin D deficiency is related to decreased bone mass in children and with a high increase in the risk of fractures, particularly at distal radius .
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Vitamin D Can Help Treat Hypertension
According to a 2019 review published in the journal Current Protein & Peptide Science suggests that vitamin D may play a role in treatment of high blood pressureone of the markers of cardiovascular diseasesays Newgent. According to authors of the review, even short-term vitamin D deficiency may directly raise BP and promote target organ damage. The researchers went on to add that, “due to the high correlation between vitamin D and hypertension, vitamin D supplementation therapy may be a new insight in the treatment of hypertension.”
How Ethnicity May Affect Your Need For Vitamin D
People who live in colder climates generally need more vitamin D than those who live closer to the equator, but among all geographic locations, people with darker skin tones often need more of the vitamin than those with lighter skin. Indeed, people with highly pigmented skin who live in cold climates are considered to be at a particularly high risk of vitamin D deficiency, according to a study published in June 2017 in the Journal of the American Academy of Dermatology. 31404-4/fulltext” rel=”nofollow”> 13)
Observationally, weve seen that people of African descent and people of Middle Eastern descent also need more vitamin D to achieve optimum levels, Foroutan says.
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