Monday, May 30, 2011

Could the asthma upsurge be due to sunlight and vitamin D deficiency?


According to the Centers for Disease Control in May 2011, “about one in 12 people in the United States now has asthma—a total of 24.6 million people and an increase of 4.3 million since 2001.”[1]

Researchers in Boston have hypothesized that the decrease in sunlight exposure and resultant vitamin D deficiency is responsible for the asthma epidemic.[2] Others show the same facts: the increase in asthma has paralleled the decline in sunlight exposure, and asthma risk is 40% lower in children of women who have the highest vitamin D consumption during pregnancy.[3] Is it time to return to the sun?

Another study shows an asthma reduction of 52-67%.[4] In that study, THREE-YEAR- OLD CHILDREN WHOSE MOTHERS WERE IN THE HIGHEST QUARTILE OF VITAMIN D CONSUMPTION DURING PREGNANCY HAVE A 61% REDUCED RISK OF A “RECURRENT WHEEZE,” A SYMPTOM OF ASTHMA, WHEN COMPARED TO THOSE WHOSE MOTHERS WERE IN THE LOWEST QUARTILE. The researchers believed that inadequate D levels in the fetus leads to improper development of the lungs and immune system, and they demonstrated that each 100-IU increase in vitamin D consumption resulted in a 19% risk reduction.

A scientific experiment from Australia also demonstrated that when asthmatic mice were exposed to ultraviolet light, before being exposed to an asthma-causing allergen, asthma symptoms were reduced.[5] Considering the yearly $700-million expenditure for Australian asthma-treatment, regular sunlight exposure seems a small price to pay. Tanning beds, like the sun, put forth ultraviolet light to produce vitamin D. These researchers were really using tanning beds for mice! Finally, another recent study from Spain has shown that children exposed to the most sunlight have lower risks of asthma.[6]

Steroids are used as an asthma therapy, but in some individuals, asthma is resistant to steroids. However, when vitamin D3 is added to the steroid treatment, symptoms are greatly reduced.[7] Perhaps sufficient supplementation or sunlight exposure could eliminate steroid need completely. This is the bottom line: children and adults are meant to play outdoors or otherwise be exposed to non-burning ultraviolet B (UVB) light—the most natural way to produce vitamin D. Every child should have a natural life playing outdoors, and both children and adults should regularly have sunlight exposure. It is critical for human health. What a travesty to deprive our children of healthy, normal lives because the Powers of Darkness need to make money selling sunscreens. Be careful not to burn, and enjoy the sun!

[1]Vital Signs: Asthma Prevalence, Disease Characteristics, and Self-Management Education --- United States, 2001--2009 MMWR, 2011; 60(17);547-552

[2]Litonjua, A. et al. Is vitamin D deficiency to blame for the asthma epidemic? J Allergy Clin Immunol 2007;120:1031-35

[3] Camargo, C. et al. Maternal intake of vitamin D during pregnancy and risk of recurrent wheeze in children at 3 y. Am J Clin Nutr 2007;85:788-95.

[4] Devereux, G. et al. Maternal vitamin D intake and early childhood wheezing. Am J Clin Nutr 2007;85:853-59

[5]Hart, P. et al. Sunlight may protect against asthma. Perth (Australia) Telethon institute for child health research. Quoted in Australian AP Oct 24, 2006.

[6] Arnedo-Pena, A et al. Sunny hours and variations in the prevalence of asthma in schoolchildren according to the International Study of Asthma and Allergies (ISAAC) Phase III in Spain. Int J Biometeorol 2011;55:423-434.

[7]Xystrakis, E. et al. Treatment of Steroid-Resistant Asthma. J Clin Invest 2006;116:146-55

No comments: