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What
is Vitamin D? |
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Vitamin D is a fat soluble vitamin which is found in food and
ultraviolet rays from the sun. Sunlight triggers Vitamin D
synthesis which is then converted to an active form in the liver
and kidney. Vitamin D increases the body's absorption of calcium
and phosphorus, which strengthens bones and the immune system. |
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What
are the sources of Vitamin D? |
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Vitamin D can be obtained in the three ways, through sunlight,
diet, and vitamin supplements. Sun exposure is thought to be the
most important way to take in Vitamin D. Necessary exposure
varies based on skin color, location, and age, however it is
estimated that ten to fifteen minutes of exposure two to three
times a week will suffice. Vitamin D is also found naturally in
fish and oysters, and can also be found in fortified dairy
products including butter, cream, milk, and margarine, and in
fortified cereal. Many others take Vitamin D supplements if
their lifestyle results in low intake levels. |
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What
is the recommended intake for Vitamin D? |
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1997 the National Academies’ Food and Nutrition Board
recommended that individuals consume between 200 and 600 IU of
Vitamin D daily. The majority of Americans do not consume even
close to this much Vitamin D, and it has been recently debated
whether or not the recommended intake be higher. The health
benefits of Vitamin D, including muscle and bone strength, cell
regulation, increased energy, stronger immune system, and
decreased chances of gum disease, cancer, and diabetes, are all
observed at higher intake levels. |
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When
can Vitamin D deficiency occur? |
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Vitamin D deficiency is a major issue in the United States.
Individuals may become deficient for a variety of reasons,
including an unbalanced diet, lack of exposure to sunlight, and
digestive problems absorbing Vitamin D. A variety of diseases
are associated with Vitamin D deficiency including rickets,
osteomalacia, and osteoporosis, all of which inflict muscle and
bone strength. |
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Who
may need extra Vitamin D to prevent a deficiency? |
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number of individuals are at a higher risk of Vitamin D
deficiency. One group which is more likely to be afflicted is
the elderly, because as humans age the skin looses its ability
to convert Vitamin D into its active form. African Americans are
also at a higher risk, because their skin converts less Vitamin
D than caucasians. Also at risk are those who have limited sun
exposure due to their northern climate or lifestyle. Infants
which are exclusively breast-fed often do not receive sufficient
amounts of Vitamin D as well as those who have diseases such as
cystic fibrosis, liver disease, or Crohn’s disease. These
diseases are accompanied by fat malabsorbtion, a reduced ability
to absorb dietary fat, which affects Vitamin D intake because
Vitamin D is a fat soluble vitamin. Individuals who are lactose
intolerant or vegans, must also be mindful of their dietary
intake of Vitamin D. |
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What
are some current issues & controversies about Vitamin D? |
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- Vitamin D has been connected to several medical issues. Less
incidence of osteoporosis, a disease distinguished by fragile
bones which typically occurs in women during menopause, and of
hip and bone fractures are linked to increased intakes of
Vitamin D. Also, early lab results have suggested that Vitamin D
may protect against colon cancer, amongst others. On the other
hand, the use of steroids and caffeine may inhibit one’s intake
of Vitamin D. |
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What
are the health risks of too much Vitamin D? |
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Vitamin D toxicity typically only occurs through the intake of
supplements. Individuals do not often overdose on Vitamin D
through their diet or through their UV ray intake. The symptoms
of Vitamin D toxicity are the result of high levels of calcium
in the blood and include high blood pressure, anorexia, nausea,
vomiting, excessive urination, increased thirst, weakness,
nervousness, itchiness, and eventually kidney failure. The
elderly are also at risk of larger brain lesions, which can
cause impairment, depression, or stroke. |
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The
keys to selecting a healthful diet: |
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Both
being active and eating right contribute to leading a healthy
lifestyle. Every individual has different dietary needs, however
there are several basics which apply to all. Foremost, diets
should have sufficient amounts of protein, fruits, vegetables,
and whole grains. Individuals should also work to limit their
portions and calorie intake. Lastly, intake of saturated fat,
trans fat, cholesterol, sugar, salt, and alcohol should be
limited.
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