A new study published in Science Daily (Jan 27, 2008) suggests that vitamin D supplements may suppress the immune system and worsen certain conditions. The researchers acknowledge that vitamin D from sunlight is important for health. In the past years several studies have shown that vitamin D deficiencies contribute to many diseases, including a number of autoimmune diseases.
Prevalence of Vitamin D Deficiency
Today, many doctors order blood tests for 25-hydroxy vitamin D. Results show that vitamin D deficiency is common in people of all ages. In another report published in Science Daily in July, 2007, researchers reported that many otherwise healthy children and adolescents have low vitamin D levels. The article reports that vitamin D deficiency puts children at risk for bone diseases such as rickets.
In adults, vitamin D deficiency contributes to bone loss, causing conditions of osteopenia and osteoporosis. Vitamin D deficiency is also widely seen in patients with multiple sclerosis. Vitamin D deficiency is considered an environmental risk factor for autoimmune disease.
Problems with Supplements
Trevor Marshall, Ph.D. a professor at Australia’s Murdoch School of Biological Medicine and Biotechnology explains that increased ingestion of vitamin D affects more than bone health. The Vitamin D receptor, a protein on cells that reacts with vitamin D molecules is involved in the repression or transcription of hundreds of genes associated with diseases ranging from cancers to multiple sclerosis. The Vitamin D receptor also regulates innate immunity particularly the body’s natural antimicrobial peptides.
By persistently activating the Vitamin D receptor with vitamin D3 supplements, other natural proteins are prevented from reacting with the vitamin D receptor. This ultimately suppresses the immune system.
Natural Vitamin D
Normally, the body receives adequate vitamin D from 10-15 minutes of daily exposure to the sun. The skin absorbs vitamin D, which it stores and utilizes as needed. Supplements, by binding to the Vitamin D receptor, block natural vitamin D hormone. Marshall’s study, which has been confirmed by other researchers, shows that even normal doses of vitamin D supplements can suppress the proper operation of the immune system and interfere with the regulation of gene expression for more than 1,000 genes.
In addition, Marshall writes that vitamin D deficiency may be a sign of disease rather than a cause of disease.
Resources:
Vitamin D Deficiency Study Raises New Questions about Disease and Supplements, written in collaboration with the Autoimmunity Research Foundation, Science Daily, Jan 27, 2008
Low Vitamin D Levels May be Common in Otherwise Healthy Children, Science Daily, July 10, 2007.
