There are five different types of Vitamin D (D1, D2, D3, D4 & D5), but D2 and D3 are the only types that our bodies can use. When something just says “vitamin D” it is generally referring to D2 or D3 (or a combination of the two).
Vitamin D is a prohormone, which is the precursor to a hormone. In its raw form (sun exposure, foods, supplements), Vitamin D is inert and has to go through a series of complex biochemical reactions before your body can use it. These reactions produce calcitriol, which is the form of Vitamin D that is used by your body (D2 and D3).
Vitamin D is one of the only vitamins that your body can produce by itself. What is the catalyst that gets your D production going? Good old fashioned sunshine! It’s the ultraviolet-B radiation (UVB) that enables vitamin D production to occur in the skin.
Vitamin D is produced in equal amounts in both people with fairly pigmented and darkly pigmented skin after exposure to UVB radiation (sunlight). Sunlight is important for Vitamin D production, but the strength of sunlight and the intensity of UVB exposure can be affected by season, distance from the equator, and even personal habits. If you have a job that keeps you indoors during daylight hours, or you work nights, you don’t produce as much Vitamin D as someone who is outside for at least ten to fifteen minutes each day.
Vitamin D can be supplemented by eating the right foods. See my previous blogpost about foods containing Vitamin D.
Benefits of Vitamin D
Vitamin D plays an important role in bone building by enabling calcium uptake by your body. It is also very important for healthy immune system function and may help lower your risk of contracting colds. Vitamin D also helps confer innate immunity which may protect your body from the influenza virus.
Vitamin D has been linked to the prevention of many different diseases, including multiple sclerosis, arthritis and even cancer. Children with higher vitamin D levels are less likely to suffer from asthma and allergies than those who are vitamin D deficient. Mental agility might be maintained by adequate levels of the vitamin, especially in the elderly.
Because Vitamin D promotes calcium absorption, it is important for bone mineralization (hardening), which keeps your bones strong and supple. A sufficient amount of Vitamin D helps prevent joint pain and osteoporosis.
There is also evidence suggesting that Vitamin D may play an important role in weight loss, both in adults and in children. Some researchers are exploring whether vitamin D may act as a natural protector from low levels of radiation, such as the background radiation we receive from sunlight and other sources.
Symptoms & Causes of Vitamin D Deficiency
There are no clearly defined causes of vitamin D deficiency, however the obvious culprits are not eating right and a lack of activity in general, but especially outdoor activity. Adults and children who have poor diets are especially at risk. Risk factors for being vitamin D deficient include race, gender, and lifestyle, including time spent watching TV, playing video games or sitting in front of the computer.
People at high risk of having Vitamin D Deficiency Syndrome (VDDS) are often those who suffer from other disorders, such as autoimmune diseases, heart disease, osteoporosis, chronic pain and fatigue, and certain cancers. Symptoms for some of these disorders can be lessened by taking a Vitamin D supplement or eating more foods with vitamin d.
Other diseases and disorders, such as rickets, rheumatism, and osteoporosis (bone disease) can be exascerbated by a lack of vitamin D in the body. Hypocalcemic tetany, a condition in which the body is low in calcium due to vitamin D deficiency, casues overactive neurological reflexes, spasms of the extremeties (hands and feet) and larynx, and muscle cramps. Calcitriol, the form of vitamin D your body uses, plays a key role in the maintenance of many organ systems.
Vitamin D Side Effects
While essential to organ, bone and immune system health, it is not advisable to exceed the recommended dosage of vitamin D unless you are under the care of a medical doctor.
Taking too much vitamin D (more than 5000 IU per day) over a long period of time may cause excess calcium levels in the blood, which can worsen conditions like atherosclerosis (hardening of the arteries), kidney stones, histoplasmosis (a fungus that is breathed in and grows in the lungs, possibly spreading to other organs), hyperparathyroidism, and lymphoma.
February 1st, 2011 at 9:28 am
Can you please list resources that support your claims? I hate when I read an article full of claims but lacking the origin of those claims. Where did you find the side effects of taking too much D? I’ve never heard of them before nor have I heard them mentioned by some one else. The article is too shallow and is a horrible pitch for the supplement. Either explain fully each claim, (for side effects or deficiency) or support your claims with resources. It will give you better credibility. I had to research each one of your claims for side effects and I couldn’t find any links between D and your mentioned conditions.
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Natalie replied on February 1st, 2011:
ummmm.. I’m certainly no expert, but it looks like every “claim” is linked to a credited source, for both the benefits and the side effects of vitamin d. But, since you somehow missed the link to the side effects, i’ll just leave it right here.
http://www.nlm.nih.gov/medlineplus/druginfo/natural/929.html#Safety
Maybe you should fully read and click on the links in the article before making shallow criticisms.. Just a thought. Cheers!
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December 16th, 2009 at 3:55 am
Vitamin D is very essential for bones and especially for growing kids. I was aware of this fact but you have mentioned much elaborated description of Vitamin D and the diseases caused by deficiency of it. I was not aware of all these diseases, which you have mentioned here.
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December 10th, 2009 at 5:24 am
I wasn’t aware of the fact that deficiency of Vitamin D can cause serious diseases like Lymphoma, atherosclerosis , kidney stones & histoplasmosis. Thanks for sharing this information with us all.
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tracy reinert replied on April 27th, 2011:
Ummmm… He said the exact opposite… Too much vitamin D can lead to these conditions.
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