Access to our free, extensive, easy-to-read Library of Information

 (see this sample page)

and Physicians' Reference Library is available to anyone, without enrollment in our counseling program. If you're interested in using this resource, please send a request to our email

 address along with your doctor's name and fax number (in the US or Canada) or his/her email address, so we can notify your doctor that you have access to this information.

A list of the articles in our libraries is available at this link.

 Physicians may use CIR libraries even if they don't have a patient enrolled in our counseling program. Interested medical practitioners should contact CIR and ask to register.

Volunteers who have a diagnosis of autoimmune or inflammatory disease or are chronically ill but who are not being treated with Inflammation Therapy, the Marshall Protocol or the Stillpoint Protocol are needed to be in the control group of our clinical study. If you meet these criteria and would like to take part in this project (which will only take a few minutes

each month), please 

contact us at our  

email address.

  "Thanks for the effort to track (data via survey),

it will be the underpinnings of this treatment at some time." ~James Graves

Vitamin D metabolites

Although vitamin D is commonly called a vitamin, it is not an essential dietary vitamin because it can be synthesized in adequate amounts by all mammals from sunlight. Vitamin D was misnamed when it was discovered in 1922.

Vitamin D has several metabolites but the most common use of the term refers to the major circulating form, the pro-hormone 25-D.

25-D is also known as calciferol, calcidiol, 25-hydroxycholecalciferol or 25-hydroxyvitamin-D. Several forms of 25-D exist (D1, D2, D3, D4, D5). The two major forms are vitamin D2 or ergocalciferol, and vitamin D3 or cholecalciferol. 25-D without a subscript refers to either D2 or D3 or both. These are known collectively as calciferol.

Calciferol (25-D) is converted to calcidiol (25-D) in the liver. Calcidiol is, primarily, used in the production of 1,25-D (the active D-metabolite).

25-D is usually the only D-metabolite measured (using ng/ml) to determine if a patient is deficient in vitamin D. Two forms of 25-D (D3 and D2) are often tested.

Measures of D3 (cholecalciferol) serum levels reflect endogenous synthesis from exposure to sunlight as well as intake from the diet (naturally from animal products) and artificially from supplementation.

Measures of D2 (ergocalciferol) serum levels reflect the presence of the form of 25-D which is produced by some organisms of phytoplankton, invertebrates, yeasts, and higher fungi such as mushrooms.

25-D is unique because it functions as a pro-hormone and because the body can synthesize it (as vitamin D3) when sun exposure is adequate (hence its nickname, the "sunshine vitamin"). 

1,25-D (the active metabolite)

25-D (calcidiol) is converted by the kidneys (and other tissues) to 1,25-D, the biologically-active vitamin D metabolite.

1,25-D is also known as calcitriol or 1,25-dihydroxycholecalciferol or 1,25-dihydroxyvitamin-D3. 1,25-D (a potent paracrine mediator) circulates as a secosteroid hormone in the blood (a hormone is a chemical substance produced by one organ and then transported in the bloodstream to a target organ, where it causes a specific biological action) and affects almost all cellular activity.

When discussing vitamin D, it's important to differentiate the pro-hormone form (25-D) from the active hormone form (1,25-D).