Celiac.com 05/11/2015 - Many people with celiac disease know that gluten exposure can cause gut damage and trouble absorbing some vitamins and minerals, which can lead to serious deficiencies. However, even celiac who follow gluten-free diets may experience similar issues, including impaired vitamin and mineral absorption.
The most common vitamin and mineral deficiencies in celiac patients include the following vitamins and minerals:
B vitamins, especially B12 Vitamin A Vitamin D Vitamin E Vitamin K Iron Calcium Carotene Copper Folic acid Magnesium Selenium Zinc As a result, patients with celiac disease can develop iron-deficiency anemia, including a type that resists oral iron supplementation...

Celiac.com 08/16/2018 - What is the significance of vitamin D serum levels in adult celiac patients? A pair of researchers recently set out to assess the value and significance of 25(OH) and 1,25(OH) vitamin D serum levels in adult celiac patients through a comprehensive review of medical literature.
Researchers included F Zingone and C Ciacci are affiliated with the Gastroenterology Unit, Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy; and the Celiac Center, AOU San Giovanni di Dio e Ruggi di Aragona, University of Salerno, Department of Medicine and Surgery, Salerno, Italy. 
Within the wide spectrum of symptoms and alteration of systems that characterizes celiac disease, several studies indicate a low-level of vitamin D, therefore r...

Celiac.com 06/28/2019 (originally published 07/12/2010) - The report by R.H. Wasserman titled “Vitamin D and the Dual Processes of Intestinal Calcium Absorption“ is very important.  I have some writing to do (and corrections to make) as a result of reading this.  It helps to explain why dogs don’t suffer from clinical osteoporosis.  It’s obvious that there are processes taking place in the ileum of humans that do not take place in the dog.  
This came up as I was counseling an Internet acquaintance concerning his osteoporosis.  He was not improving with conventional therapy and was also suffering from chronic lymphocytic colitis.  I knew that the ileum actively absorbs calcium but the numbers in the study above were news to me.  I’ve been telling people for years that one of the b...