Vitamin D, also known as calciferol, is a steroid vitamin, and is needed for normal absorption of calcium and phosphorus. It helps put these minerals into bones and teeth. This makes bones stronger and reduces your risk for bone fractures. Vitamin D also helps keep the immune system functioning helping the body resist disease.
Vitamin D is found in many dietary sources, such as fish, eggs, fortified milk, and cod liver oil. The sun also contributes significantly to the daily production of vitamin D, and as little as 10 minutes of exposure is thought to be enough to prevent deficiencies. People who are exposed to normal quantities of sunlight do not need vitamin D supplements because sunlight promotes sufficient vitamin D synthesis in the skin.
The term "vitamin D" refers to several different forms of this vitamin. Two forms are important in humans: ergocalciferol (vitamin D2), which is found in such foods; and cholecalciferol (vitamin D3), which is manufactured when the body is exposed to sun. Vitamin D2 is synthesized by plants. Vitamin D3 is synthesized by humans in the skin when it is exposed to ultraviolet B (UVB) rays from sunlight. Foods may be fortified with vitamin D2 or D3.
You can get vitamin D in three ways: through your skin, from your diet, and from supplements. Your body forms Vitamin D naturally after exposure to sunlight. However, too much sun exposure can lead to skin aging and skin cancer. So many people try to get their vitamin D from other sources.
Vitamin D is one of those vitamins for which a deficiency can cause severe effects. Children that do not get enough vitamin D in their diets are at increased risk of developing rickets, a disease that causes malformations of bones and teeth in children. Adults with low levels of vitamin D are more likely to develop osteomalacia (similar to rickets) and to suffer from osteoporosis, a bone-weakening disease. Vitamin D also regulates the nervous system, aiding in the treatment of insomnia. A glass of warm milk before bed may indeed help you sleep soundly! Vitamin D deficiency has also been linked to the development of other illnesses, including type I diabetes, muscle and bone pain, and cancer.
Vitamin D is fat-soluble. This means that excess amounts of it are stored in the body tissues. Long-term high doses may be deposited in the soft tissues, irreversibly damage the kidneys and cardiovascular system. Like other fat-soluble vitamins, vitamin D can be toxic. Symptoms of too much vitamin D include nausea, weakness, constipation, irregular heartbeat, weight loss, seizures, and irritability.
Sunlight is the best source of vitamin D, because sunlight exposure does not cause vitamin D toxicity, and 10 minutes of sun on your hands and face provides enough vitamin D to reach the daily value. However, getting the necessary amount of vitamin D from the sun is not as simple as it sounds. For one thing, people in northern hemisphere may have difficulty getting vitamin D from sun in the winter due to infrequent exposure to direct sunlight (light coming through a glass window of a car or building doesn't count, because it filters out vitamin D). Also, the recent explosion in the number of skin cancer cases has caused the public to use more and stronger sunscreen, which inhibits the body's ability to manufacture its own vitamin D from sunlight. However, if you have a history of skin cancer, it is probably best to try to get the vitamin D needed from your diet instead rather than the sun.
The major source of vitamin D in our diet is fortified milk, but it would take one quart of fortified milk to provide the Daily Value. Because there are relatively few foods that contain vitamin D, you may wish to rely on a vitamin supplement to meet your daily needs (see "Proper Dosing").
Vitamin D is used for preventing and treating rickets, a disease that is caused by not having enough vitamin D (vitamin D deficiency). Vitamin D is also used for treating weak bones (osteoporosis), bone pain (osteomalacia), bone loss in people with a condition called hyperparathyroidism, and an inherited disease (osteogenesis imperfecta) in which the bones are especially brittle and easily broken. It is also used for preventing falls and fractures in people at risk for osteoporosis, and preventing low calcium and bone loss (renal osteodystrophy) in people with kidney failure.
Vitamin D is used for conditions of the heart and blood vessels, including high blood pressure and high cholesterol. It is also used for diabetes, obesity, muscle weakness, multiple sclerosis, rheumatoid arthritis, chronic obstructive pulmonary disease (COPD), asthma, bronchitis, premenstrual syndrome (PMS), and tooth and gum disease.
Some people use vitamin D for skin conditions including vitiligo, scleroderma, psoriasis, actinic keratosis, and lupus vulgaris.
It is also used for boosting the immune system, preventing autoimmune diseases, and preventing cancer.
Because vitamin D is involved in regulating the levels of minerals such as phosphorous and calcium, it is used for conditions caused by low levels of phosphorous (familial hypophosphatemia and Fanconi syndrome) and low levels of calcium (hypoparathyroidism and pseudohypoparathyroidism).
Vitamin D in forms known as calcitriol or calcipotriene is applied directly to the skin for a particular type of psoriasis.
There is a vast body of science showing the many health benefits of vitamin D. You may be surprised to learn the important role that vitamin D plays in your health.
Maintains Your Calcium Balance -- Maintenance of blood calcium levels within a narrow range is vital for normal functioning of the nervous system, as well as for bone growth, and maintenance of bone density. Vitamin D is essential for the efficient utilization of calcium by the body.
Maintains Your Weight -- Population studies have found that people who have lower levels of vitamin D are more likely to be obese compared to people with higher levels of vitamin D. One high-quality study also found that postmenopausal women who took 400 IU vitamin D plus 1,000 mg calcium daily for 3 years were less likely to gain weight than those who took placebo, although the weight difference was small. Women who were not getting enough calcium to start with (less than 1,200 mg per day) saw the most benefit.
Aids Your Cell Differentiation -- Cellular differentiation results in the specialization of cells for specific functions in your body. In general, differentiation of cells leads to a decrease in proliferation. While cellular proliferation is essential for growth and wound healing, uncontrolled proliferation of cells with certain mutations may lead to diseases like cancer. The active form of vitamin D, inhibits proliferation and stimulates the differentiation of cells.
Boosts Your Immunity -- Active vitamin D is a potent immune system modulator. There is plenty of scientific evidence that vitamin D has several different effects on immune system function that may enhance your immunity and inhibit the development of autoimmunity.
Has a Role in Insulin Secretion -- The active form of vitamin D plays a role in insulin secretion under conditions of increased insulin demand. Limited data in humans suggests that insufficient vitamin D levels may have an adverse effect on insulin secretion and glucose tolerance in type 2 diabetes. More studies are needed on the role of vitamin D and diabetes.
Blood Pressure Regulation -- Adequate vitamin D levels may be important for decreasing the risk of high blood pressure. Again, more studies on vitamin D and hypertension are necessary.
According to the National Institutes of Health, vitamin D may play a role in the following diseases.
Vitamin D and Osteoporosis -- Osteoporosis is most often associated with inadequate calcium intake. However, a deficiency of vitamin D also contributes to osteoporosis by reducing calcium absorption. While rickets and osteomalacia are extreme examples of vitamin D deficiency, osteopororsis is an example of a long-term effect of vitamin D insufficiency. Adequate storage levels of vitamin D help keep bones strong and may help prevent osteoporosis in older adults, in those who have difficulty walking and exercising, in post-menopausal women, and in individuals on chronic steroid therapy.
Vitamin D deficiency, which is often seen in post-menopausal women and older Americans, has been associated with greater incidence of hip fractures. In a review of women with osteoporosis hospitalized for hip fractures, 50 percent were found to have signs of vitamin D deficiency. Daily supplementation with 20 800 IU of vitamin D may reduce the risk of osteoporotic fractures in elderly populations with low blood levels of vitamin D. The Decalyos II study examined the effect of combined calcium and vitamin D supplementation in a group of elderly women who were able to walk indoors with a cane or walker. The women were studied for two years, and results suggested that such supplementation could reduce the risk of hip fractures in this population.
Vitamin D and Cancer -- Laboratory, animal, and some preliminary human studies suggests that vitamin D may be protective against some cancers. Several studies suggest that a higher dietary intake of calcium and vitamin D correlates with lower incidence of cancer. In fact, for over 60 years researchers have observed that greater sun exposure reduces cancer deaths. The inverse relationship between higher vitamin D levels in blood and lower cancer risk in humans is best documented for colon and colorectal cancers. Vitamin D emerged as a protective factor in a study of over 3,000 adults who underwent a colonoscopy to look for polyps or lesions in the colon. There was a significantly lower risk of advanced cancerous lesions among those with the highest vitamin D intake.
Additional clinical trials need to be conducted to determine whether vitamin D deficiency increases cancer risk, or if an increased intake of vitamin D is protective against some cancers. Until such trials are conducted, it is premature to conclude you should take vitamin D supplements for cancer prevention.
Vitamin D and Alzheimer's Disease -- Alzheimer's disease is associated with an increased risk of hip fractures because many Alzheimer's patients are homebound, frequently sunlight deprived, and older. With aging, less vitamin D is converted to its active form. One study of women with Alzheimer's disease found that decreased bone mineral density was associated with a low intake of vitamin D and inadequate sunlight exposure. More investigation on vitamin D and Alzheimers Disease is necessary.
Autoimmune Diseases - Diabetes, Multiple Sclerosis and Rheumatoid Arthritis -- Diabetes mellitus, multiple sclerosis, and rheumatoid arthritis, are each examples of autoimmune disease. Autoimmune diseases occur when the body launches an immune response to its own tissue, rather than a foreign pathogen. Treatment with vitamin D has beneficial effects in animal models of all of the above mentioned diseases. Studies have found that the prevalence of diabetes, multiple sclerosis, and rheumatoid arthritis increases as latitude increases, suggesting that lower exposure to sun light and associated decreases in vitamin D synthesis may play a role in the development of these diseases.
The results of several studies also suggest that adequate vitamin D intake may decrease the risk of autoimmune diseases. Evidence from animal models and human studies suggests that maintaining sufficient vitamin D levels may help decrease the risk of several autoimmune diseases, but more studies are needed to draw any solid conclusions.
Vitamin D and Hypertension (High Blood Pressure) -- The results of epidemiological and clinical studies suggest an inverse relationship between serum vitamin D levels and blood pressure. Data from epidemiological studies suggest that conditions that decrease vitamin D synthesis in the skin, such as having dark skin and living in temperate latitudes, are associated with increased prevalence of hypertension. In randomized controlled trials of vitamin D supplementation, a combination of 1,600 IU/day of vitamin D and 800 mg/day of calcium for eight weeks significantly decreased systolic blood pressure in elderly women by 9% compared to calcium alone, but supplementation with 400 IU/day or a single dose of 100,000 IU of vitamin D did not significantly lower blood pressure in elderly men and women over the next two months. At present, data from controlled clinical trials are too limited to determine whether vitamin D supplementation will be effective in lowering blood pressure or preventing hypertension.
Vitamin D is required for the regulation of the minerals calcium and phosphorus found in the body. It also plays an important role in maintaining proper bone structure.
Sun exposure is an easy, reliable way for most people to get vitamin D. Exposure of the hands, face, arms, and legs to sunlight two to three times a week for about one-fourth of the time it would take to develop a mild sunburn will cause the skin to produce enough vitamin D. The necessary exposure time varies with age, skin type, season, time of day, etc.
It's amazing how quickly adequate levels of vitamin D can be restored by sunlight. Just 6 days of casual sunlight exposure without sunscreen can make up for 49 days of no sunlight exposure. Body fat acts like a kind of storage battery for vitamin D. During periods of sunlight, vitamin D is stored in fatty fat and then released when sunlight is gone.
Nevertheless, vitamin D deficiency is more common than you might expect. People who don't get enough sun, especially people living in Canada and the northern half of the US, are especially at risk. Vitamin D deficiency also occurs even in sunny climates, possibly because people are staying indoors more, covering up when outside, or using sunscreens consistently these days to reduce skin cancer risk.
Older people are also at risk for vitamin D deficiency. They are less likely to spend time in the sun, have fewer "receptors" in their skin that convert sunlight to vitamin D, may not get vitamin D in their diet, may have trouble absorbing vitamin D even if they do get it in their diet, and may have more trouble converting dietary vitamin D to a useful form due to aging kidneys. In fact, the risk for vitamin D deficiency in people over 65 years of age is very high. Surprisingly, as many as 40% of older people even in sunny climates such as South Florida don't have enough vitamin D in their systems.
Vitamin D supplements may be necessary for older people, people living in northern latitudes, and for dark-skinned people who need extra time in the sun, but don't get it.
Main article: Vitamin D Deficiency
Lack of vitamin D affects bones and many other parts of the body. Growing children who do not get enough vitamin D may have bones that can't support their weight (rickets). Adults deficient in vitamin D can develop soft bones (osteomalacia). They also can lose bone mass, which leads to fragile bones (osteoporosis).
Vitamin D deficiency symptoms appear more as various disorders. These symptoms include:
Rickets -- It is the most frequent vitamin D deficiency symptom in children. As a result of vitamin D deficiency, the bones are weakened, the bone tissue fail to mineralize leading to soft and deformed bones.
Osteoporosis -- Osteoporosis happen when the amount of minerals in bones lower bellow certain threshold and your bones become more fragile and sensitive. It mostly affects women but it can also affect men.
Depression and Fatigue -- According to scientists, depression is the result of the lack of vitamin D. They argue that because of urbanization, the sunlight can't adequately reach the skin, reducing thus the 25(OH) level in the body, causing depression. It has been also discovered that a great number of people suffer from seasonal affective disorder during the winter due to insufficient exposure to direct sunlight. The parathyroid hormone is the one causing the vitamin D deficiency symptom of depression.
Hyperparathyroidism -- Results from hypocalcemia, which is a blood condition with unusually low vitamin D level, resulting in hyperparathyroidism.
Obesity -- Vitamin D deficiency is frequently linked to obesity, as the insufficient level of vitamin D holds back the production of hormone leptin, which regulates the fat in the body. Inadequate exposure to sunlight disrupts the normal function of the body, determining the individual to eat more than it is necessary for the body.
Osteomalacia -- When rickets happen to adult person, condition is then named Osteomalacia. Also Osteomalacia is often used as a name for later stages of rickets regardless of patient age. Main cause for this condition is deficiency of vitamin D.
The list of vitamin D deficiency symptoms also includes: chronic backache, cancers, chronic pain, diabetes, multiple sclerosis, heart diseases or hypertension.
Pregnant women could -- and probably should -- consume 10 times more vitamin D than experts currently recommend, according to a new study.
Current guidelines [before November 2010] for daily vitamin D intake during pregnancy range from 200 international units (IU) per day to 400 IU, the amount found in most prenatal vitamins. For decades, doctors have worried that too much vitamin D during pregnancy could cause birth defects, and under current guidelines anything over 2,000 IU per day is still considered potentially unsafe for anyone, not just pregnant women.
That much vitamin D is not only safe during pregnancy, the researchers say, but doubling it may actually reduce the risk of complications.
Pregnant women should not change their vitamin D intake without consulting their physicians, however. The study looked only at women in their second trimester and beyond, and it's not yet clear whether high doses of vitamin D are safe earlier in pregnancy, when organs are formed and the fetus is especially vulnerable to birth defects.
In the study, 500 women who were at least 12 weeks pregnant took either 400, 2,000, or 4,000 IU of vitamin D per day. The women who took 4,000 IU were least likely to go into labor early, give birth prematurely, or develop infections.
"Pregnant women need to take 4,000 IU of vitamin D a day," says Bruce Hollis, Ph.D., the director of pediatric nutritional sciences at the Medical University of South Carolina, in Charleston, and one of the authors of the study. "We didn't see a single adverse effect. It was absolutely safe, and we saw a lot of improved outcomes. The risk of preterm labor was vastly decreased and so was the risk of other complications of pregnancy."
Hollis and his colleagues presented their research today at the annual meeting of the Pediatric Academic Societies in Vancouver, B.C.
Taking supplements is the only practical way to consume that much vitamin D. "You can't drink that much milk," Hollis says. "You take prenatal vitamins for other things, but the amount [of vitamin D] in a prenatal vitamin is useless."
The findings are a sign that current vitamin D guidelines are far too low, says Elisa Ross, M.D., a staff physician at the Cleveland Clinic Institute of Women's Health, in Ohio. "In the olden days, we thought vitamin D could be associated with certain birth defects and may cause more calcium to build up in the women's blood. If this study is confirmed -- which I am hoping it will be -- it will increase the amount of vitamin D we recommend 10-fold."
The levels of vitamin D recommended in the new study are sensible, Holick says. Previous research suggests that pregnant women who get too little vitamin D are more likely to develop life-threatening high blood pressure (preeclampsia) and are also more likely to require a Cesarean section, he says.
"Giving 4,000 IU a day to pregnant women not only doesn't cause toxicity, but may improve birth outcomes," Holick says. "The risks of vitamin D during pregnancy are overblown and the benefits are understated."
Prompted by the recent flood of research on vitamin D deficiency, the Institute of Medicine, an independent organization that advises the U.S. government on health matters, is now considering whether to raise its guidelines for vitamin D intake, including those for pregnant women (200 IU per day) and the maximum safe daily dose (2,000 IU). The new guidelines are expected to be announced this summer (see "Proper Dosing" below).
We need to get enough vitamin D from all sources to have adequate levels of this vitamin in our blood. Recent research indicates that Americans need to get more vitamin D than we used to think was needed. Older adults and persons with dark skin are at higher risk than others for having low levels of vitamin D in their bodies.
Adequate daily intakes for dietary vitamin D are listed below. Seniors and people who don't get exposed to much sunlight may need to take supplements. Seniors may be at risk of developing vitamin D deficiency because as we age, the body does not make as much vitamin D from sunlight, and it has a harder time converting vitamin D into a form it can use.
After being commissioned by the Canadian and American governments, the Institute of Medicine (IOM) as of 30 November 2010, has increased the tolerable upper limit (UL) to 1000 IU for infants (birth to 12 months), 2500 IU per day for ages 1–3 years, 3000 IU per day for ages 4–8 years and 4000 IU per day for ages 9–71+ years (including pregnant or lactating women).
In 2010, the Institute of Medicine set new Recommended Daily Allowances, or RDAs, of vitamin D for most children and adults. However, individuals at risk of low vitamin D may need more than the RDA. Therefore, The Endocrine Society guidelines suggest intakes (the amounts of vitamin D an individual should consume) for at-risk people. The table shows both sets of advice and the upper limit (highest intake) thought to be safe.
Suggested Vitamin D Intake |
||||
|
|
General Population (Institute of Medicine Recommendation) |
At Risk of Vitamin D Deficiency (The Endocrine Society Suggestions) |
||
|
Age |
RDA (IU/day)* |
Upper Limit (IU/day) |
Daily Recommendation (IU/day)* |
Upper Limit (IU/day) |
|
Infants and children |
||||
|
0–6 months |
— |
1000 |
400–1000 |
2000 |
|
6–12 months |
— |
1500 |
400–1000 |
2000 |
|
1–3 years |
600 |
2500 |
600–1000 |
4000 |
|
4–8 years |
600 |
3000 |
600–1000 |
4000 |
|
9–18 years |
600 |
4000 |
600–1000 |
4000 |
|
Adults |
||||
|
19–70 years |
600 |
4000 |
1500–2000 |
10000 |
|
>70 years |
800 |
4000 |
1500–2000 |
10000 |
|
Pregnant or breast-feeding |
||||
|
14–18 years |
600 |
4000 |
600–1000 |
4000 |
|
19–50 years |
600 |
4000 |
1,500–2000 |
10000 |
|
IU = International Units |
||||
* Many researchers have suggested that the recommended daily intakes for vitamin D are too low. The National Institutes of Health, which sets the amounts, is reviewing the research. It is advised to follow the upper day limit for maintaining a good health. If you are concerned about your vitamin D levels, ask your doctor whether you should take a supplement, and how much.
It is recommended that pregnant women get 4000 IU of vitamin D a day and breastfed infants get 4000 to 6000 IU of vitamin D daily until they are weaned and drinking at least 1 liter of whole milk or formula fortified with vitamin D. It is also recommended that children and teens who drink less than 1 liter of milk a day take 1000 to 2000 IU of vitamin D.
Due to Vitamin D's high safety profile in doses up to 10,000 IU per day and because of the wide role it plays in our health, consuming 2,000 to 4,000 IU per day of this nutrient at times of the year when sunlight is scarce is a prudent way to improve overall health.
We get vitamin D from three sources—food, supplements, and sunlight.
Food: Eggs, sardines, and salmon contain vitamin D. Most fluid milk and some brands of yogurt are fortified with vitamin D. Fortified breakfast cereals, breads, and orange juice also may contain this vitamin. Here are some foods and the amount of vitamin D they typically contain:
|
Food |
Vitamin D (IU) |
|
Salmon, cooked, 3 oz |
320 |
|
Sardines, canned in oil, 3 oz |
240 |
|
Shrimp, canned, 3 oz |
100 |
|
Fortified orange juice, ¾ cup |
90 |
|
Cereal, fortified, 1 serving |
40 or more |
|
Egg yolk, cooked, 1 large |
25 |
|
oz = ounces |
IU = International Units |
Supplements: If you can't get enough vitamin D from your diet, and you don't get out in the sun much, a supplement can help. It is recommended that older adults and persons with dark skin get extra vitamin D from fortified foods or supplements.
Sunlight: When exposed to sunlight, the skin makes vitamin D, which is then activated in the body. Most people get some vitamin D from sunlight. However, several factors affect how well the body makes vitamin D after the skin is exposed to sunlight. For example, people in the northern U.S. make less vitamin D than those in the south, especially in the winter when the sun is lower in the sky. In general, the following people may be at risk for vitamin D deficiency:
Older people
Persons with dark skin
People who are obese or who have kidney or liver disease
People who do not get enough direct sun exposure
Since skin synthesis of vitamin D varies so much, the latest dietary recommendations assume minimal sun exposure.
Some side effects include rexcessive thirst, dry mouth, metallic taste in mouth, poor appetite, bone pain, tiredness, sore eyes, itchy skin, nausea and vomiting, constipation, diarrhea, a frequent need to urinate, and mMuscle problems. Toxicity associated with long-term and high-dose use includes: polydipsia, depression, headache, drowsiness, weakness, calcium and bone loss, hypercalcemia, and metastatic calcification of soft tissues in kidney, heart, blood vessels, and lung.
Excess vitamin D intake may increase the risk of falls or fractures. Other potential adverse effects include increased risk of urinary tract infections, decreased appetite, weight loss, an elevated international normalized ratio, hypercalcemia (increased calcium in the blood), hypercalciuria (increased calcium in the urine), hypervitaminosis D (high blood levels of vitamin D), elevated creatinine levels, gastrointestinal complaints, and increased cancer risk.
Very high doses of vitamin D can cause serious health concerns. Two women developed life-threatening hypercalcemia resulting from intake of over-the-counter vitamin-D concentrated supplements that were 100 — 1,000 times higher than stated on the label.
Vitamin D toxicity can result from regular excess intake of this vitamin and may lead to hypercalcemia, hypercalciuria, and excess bone loss. Individuals at particular risk include those with hyperparathyroidism (overactive parathyroids), kidney disease, sarcoidosis, tuberculosis, or histoplasmosis (examples of immune disorders). Chronic hypercalcemia may lead to serious or even life-threatening complications and should be managed by a physician. Early symptoms of hypercalcemia may include nausea, vomiting, and anorexia (appetite or weight loss), followed by polyuria (excess urination), polydipsia (excess thirst), weakness, fatigue, somnolence, headache, dry mouth, a metallic taste, vertigo (dizziness), tinnitus (ear ringing), and ataxia (unsteadiness). Kidney function may become impaired, and metastatic calcifications (calcium deposition in organs throughout the body) may occur, particularly affecting the kidneys. Treatment involves stopping the intake of vitamin D or calcium and lowering the calcium levels under strict medical supervision, with frequent monitoring of calcium levels. Acidification of urine and corticosteroids may be necessary. To return vitamin D levels to normal, the supplement is discontinued.
Vitamin D is SAFE when taken by mouth in recommended amounts. Most people do not commonly experience side effects with vitamin D, unless too much is taken. Some side effects of taking too much vitamin D include weakness, fatigue, sleepiness, headache, loss of appetite, dry mouth, metallic taste, nausea, vomiting, and others.
Vitamin D is SAFE during pregnancy and breast-feeding when used in the amounts recommended at 4000 IU. Do not use higher doses without talking to your healthcare provider. Using higher doses might cause serious harm to the infant. One thousand micrograms (40,000 IU) per day in infants has produced toxicity within one month.
Vitamin D toxicity can cause nausea, mood changes, and organ damage. It is believed that 250 micrograms/day (10,000 IU; less for children younger than nine) of vitamin D each day from food and supplements in healthy adults are safe and can thus be adopted as the tolerable upper limit.
In healthy adults, sustained intake of more than 1250 micrograms/day (50,000 IU) can produce overt toxicity after several months; those with certain medical conditions such as primary hyperparathyroidism are far more sensitive to vitamin D and develop hypercalcemia in response to any increase in vitamin D nutrition, while maternal hypercalcemia during pregnancy may increase fetal sensitivity to effects of vitamin D and lead to a syndrome of mental retardation and facial deformities.
Kidney disease: Vitamin D may increase calcium levels and increase the risk of "hardening of the arteries" in people with serious kidney disease. This must be balanced with the need to prevent renal osteodystrophy, a bone disease that occurs when the kidneys fail to maintain the proper levels of calcium and phosphorus in the blood. Calcium levels should be monitored carefully in people with kidney disease.
High levels of calcium in the blood: Taking vitamin D could make this condition worse.
Blood sugar: Vitamin D may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia and in those taking drugs, herbs, or supplements that affect blood sugar. Blood glucose levels may need to be monitored by a qualified healthcare professional, including a pharmacist. Medication adjustments may be necessary.
Blood pressure: Vitamin D may cause low blood pressure. Caution is advised in patients taking herbs or supplements that lower blood pressure.
Hardening of the arteries (atherosclerosis): Taking vitamin D could make this condition worse.
Sarcoidosis: Vitamin D may increase calcium levels in people with sarcoidosis. This could lead to kidney stones and other problems. Use vitamin D cautiously.
Histoplasmosis: Vitamin D may increase calcium levels in people with histoplasmosis. This could lead to kidney stones and other problems. Use vitamin D cautiously.
Hyperparathyroidism: Use cautiously in patients with hyperparathyroidism, as vitamin D may increase calcium levels.
Lymphoma: Vitamin D may increase calcium levels in people with lymphoma. This could lead to kidney stones and other problems. Use vitamin D cautiously.
Allergies: Avoid with known allergy/hypersensitivity to vitamin D, any of its analogs and derivatives, or any component of the formulation.
The following reviews have been selected:
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54 of 58 people found the following review helpful:
5.0 out of 5 stars Just What The Doctor Ordered!, July 5, 2010
By
G. Lake "1233fire" (Cool, California)
When visiting my doctor and describing my symptoms of lacking energy, lack of joy, some depression and several other factors, he said that I should consider taking 5,000mg of Vitamin D3 per day. I found it interesting that he said that many of the doctors in his building are taking it since finding that after about 2 months their energy and mood levels are significantly improved. Since I am always interested in what Doctors take themselves, I decided to study why this was true, so when at Bar and Nob, I found the Vitamin D Cure by James E Dowd, MD...and was very impressed. Nearly all my symptoms were noted in the V D3 deficiency list. As a matter of fact, both my teens and my wife have symptoms of V D3 deficiency as well! When telling my wife about my exciting "find", she said that her doctor had prescribed it for her two months earlier (5,000mg/day.)... Some Vitamin D deficiency symptoms from pg 10: fatigue, joint pain/or swelling, muscle pain pain, cramping, and/or weakness (leg cramps?), chronic pain, uncontrolled weight gain, high BP, restless sleep, poor concentration and memory, headaches, bowel and bladder problems. Unless you work outside most of the time, you are probably very deficient in Vitamin D...that is most of us!...,
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6 of 6 people found the following review helpful:
5.0 out of 5 stars It actually works, April 25, 2011
By
Dr. Curmudgeon
I am not a fan of alternative medicine nor do I [think it's anything special to] nutrition, but after all the flap about Vitamin D lately, I decided to give this a try.
It actually works, which is more than I can say for most prescription medicines I've dealt with. In a period of a few months, most of the minor maladies I'd been suffering from for years just went away. I was obviously suffering from a vitamin D deficiency.
These seem like a pretty darn good value, too. I take one every other day, which means that this bottle lasts me a year. And they're tiny little things, as opposed to those calcium chokers that my doctor keeps pushing on me. Easy to swallow, and no discernable side effects.
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3 of 4 people found the following review helpful:
5.0 out of 5 stars Vitamin D3: Necessary For Excellent Health, April 5, 2011
By
ArkitekT
Vitamin D3 5000 IU is a super vitamin. With many people being vitamin D deficient, this pill taken twice daily is highly recommended for ultimate health. Vitamin D is excellent for bone health and it's fantastic for the immune system. Instead of taking the flu vaccine this year, avoid it and just try taking Vitamin D. The FDA has said that over 400 IU daily is not safe but studies have found that taking over 50,000 IU's weekly had no bad toxicity outcome. Trust me, do some research. Don't take the flu vaccine unless you research what's inside of it and stay healthy. Good day and One Love <3
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4 of 4 people found the following review helpful:
5.0 out of 5 stars Worth every penny and more..., March 18, 2011
By
R Smith
I purchased this because I am hypoglycemic (no, I am not, nor have I ever been diabetic - shocking, I know). I was [diagnosed] with hypoglycemia after gastric bypass surgery (which, happens to be a rare side effect of the surgery - but they don't tell you about that before hand). Yay me!!!
I read an article in a diabetes magazine that said Vitamin D3 regulates blood sugar. I thought, why not, since my body tells me I am fasting only 2-3 hrs after eating (and no, I do not eat huge meals. I can't. My stomach is literally the size of a large egg). Since taking these though, my body no longer feels like I've been "fasting".
I take one of these pills, once every 2-3 days, per instructions on the bottle. I have to tell you, I am impressed. My blood sugar is no longer yo-yoing, I rarely even check it (I get physical symptoms if my blood sugar is too high or too low). I was actually shocked that this tiny pill packs 5000 IUs.
The best purchase I've ever made. Will continue using/buying it.
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1 of 2 people found the following review helpful:
5.0 out of 5 stars Vitamin D and MS, March 1, 2011
By
MIke
I read Dr. Jelineks book "Overcoming MS".
He discribed how Vitamin D has a good influence on autoimmune issues especialy with MS.
So i tryed this Vitamin D supplement.
All of Dr Jelineks recommondations seem to proof as correct so far.
I will buy this Vitamin D again.
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7 of 8 people found the following review helpful:
4.0 out of 5 stars Good value, January 21, 2011
By
James L. Wright Jr. (Long Beach, CA USA)
I grew up being told to beware of Vitamin D poisoning, so it's only recently that the thought of a 5000 IU dose of Vitamin D hasn't induced fear. Recent studies and testimonials, and a blood test, had me rethinking "safe" dosages and vitamin D absorption, particularly for the obese. so I ordered a bottle.
My next blood test came back with healthy levels of vitamin D. I was surprised it wasn't "high" but I guess that confirmed the newer studies. I also noticed improved health and energy, which helped me lose 50 pounds...
I've seen both higher and lower dosages (10,000 IU, 1,000 IU) so be sure to confirm via blood tests which is best for you.
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