CajunGrl said, "The test to check you Vitamin D levels is called 25-hydroxy-vitamin D and 1,25 dihydroxy-vitamin D. It is my understanding that both of these need to be checked". Yes! That is the test you want to get to see if you are vitamin D deficient. Thank you for posting that!
Razzle, actually, vitamin D3 is known to be more effective than D2. The fact that doctors may prescribe D2 doesn't really validate the fact that D2 is better for you. If you read about
Lyme disease (or any chronic disease) and which of the two vitamins D's are recommended, vitamin D3 will almost always be the D vitamin of choice by LLMD's and LLND's.
If you want to read the scientific evidence behind this, there is good study that was done comparing Vitamins D3 and D2. It's long and boring to those of us who are "scientifically challenged", not to mention, it's a lot of reading which isn't easy for some of us lymies who have problems concentrating. But in a nutshell, here is what it says without reading the whole article which I will post a link to:
"To our knowledge, this is the first study comparing vitamins D3 and D2 by mapping the time course of serum 25OHD after a single dose. We showed that vitamin D3 raises and maintains 25OHD levels to a substantially greater degree than does vitamin D2, with a differential potency of at least 3-fold, and more likely closer to 10-fold."
Source to the full study here: jcem.endojournals.org/cgi/content/full/89/11/5387
Here's another article that supports vitamin D3 over D2 and explains why:
--Vitamin D2 and/or Vitamin D3
There are two types of vitamin D supplements available for over-the-counter purchase (vitamin D2 and vitamin D3).
Vitamin D3 is the type that most experts believe should be utilized in clinical practice (Wolpowitz & Gilchrest, 2006).
Vitamin D2 is also known as "ergocalciferol," and vitamin D3 is also known as "cholecalciferol." This is important for patients who have purchased a dietary supplement that does not indicate the specific type of vitamin D in the product by number but have listed the scientific name. Most experts now believe that the only form that should be purchased is vitamin D3. Vitamin D2 is also very acceptable, but in the author’s opinion, most individuals should switch to D3. There is a plethora of logical reasons for advocating the use of vitamin D3 over vitamin D2 dietary supplements
(Wolpowitz, & Gilchrest, 2006), including:
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 healthy fish contain vitamin D3.
Vitamin D3 is the same price as vitamin D2.
Vitamin D3 may be less toxic than D2 because higher concentrations of D2 circulate in the blood when consumed (compared to vitamin D3). It does not bind as well to the receptors in the human tissues compared to vitamin D3.
Vitamin D3 is the more potent form of vitamin D, which is a potential benefit. For example, obesity tends to lower blood levels of vitamin D, so a more potent form is needed.
Vitamin D3 is more stable on the shelf compared to D2, and is more likely to remain active for a longer period of time and when exposed to different conditions (temperature, humidity, and storage). This is perhaps why the amount of vitamin D2 in certain fortified food products have been significantly lower than that advertised on the label in numerous instances.
Vitamin D3 has been the most utilized form of vitamin D in clinical trials, and there have only been a few clinical trials of vitamin D2 to prevent bone fractures in adults.
Vitamin D3 is more effective at raising and maintaining the vitamin D blood test (again, D2 binds less tightly to the vitamin D receptors in the body; therefore, D2 does not circulate as long in the body, which means it has a shorter half-life).
Vitamin D2 is a fungus/yeast-derived product, and it was first produced in the early 1920s by exposing foods to ultraviolet light (Wolpowitz & Gilchrest, 2006). This process was patented and licensed to pharmaceutical companies.
Currently, many major prescript
ion forms of vitamin D are actually vitamin D2 and not vitamin D3. Vitamin
D2 is synthetically made from radiating a compound (ergosterol) from the mold ergot.
Vitamin D3 is made commercially and synthetically in a similar way that it is produced intrinsically in human and animal skin when exposed to UVB light. Wool sources of 7-dehydrocholesterol are used (from cholesterol), and irradiatied to form active vitamin D3. Vegetarians or especially vegans may be opposed to the use of vitamin D3 supplementation because it is derived from an animal source, and these individuals should be guided to the vitamin D2 form. Multivitamins have either vitamin D2 or D3, but many companies are now utilizing mostly vitamin D3. Cod liver oil has vitamin D3 in it.
Rickets, a defect in bone growth in infancy and childhood, was first identified in 1650 (Welch, Bergstrom, & Tsang, 2000). It was not until 1922 that medical research demonstrated that something in cod liver oil prevented and cured rickets.
Additionally, vitamin D2 added to milk in the United States and Europe in the 1930s essentially eliminated rickets (disease of weak bones in children) or osteomalacia (same disease of weak bones but in adults). Currently, fortification with vitamin D2 or D3 has continued to keep rickets scarce in North America. The minimum amount of vitamin D needed to prevent rickets is 100 IU (2.5 mcg) per day in infants with little to no sun exposure.--
Source of this article above: http://www.medscape.com/viewarticle/589256_4
While taking vitamin D2 can be helpful, it's much better to take D3 for all of the reasons stated above. I do agree that you should be tested by a doctor to determine if you are deficient in vitamin D, but I believe getting vitamin D3 drops are far more beneficial and effective than vitamin D2. If you do a google search I believe the evidence supports this.
By the way, speaking of vitamins, Dr. S who wrote the book, "The Lyme Disease Solution" has a list of supplements (D3 included) that he believes all Lyme patients should be taking. I think he's pretty much spot on. I take all of the supplements he has on his list for Lyme patients except for vitamin A. Maybe that's something I might add to my daily supplement intake. Anyone have comments on this?
Post Edited (GWB) : 5/15/2010 6:58:32 PM (GMT-6)