Vitamin D deficiency prevalence in summer compared to winter in a city with high humidity and a sultry climate.

Endokrynol Pol. 2011;62(3):249-251.

Kashi Z, Saeedian FS, Akha1 O, Gorgi MA, Emadi SF, Zakeri H.

Background: Vitamin D deficiency is high in winter because of reduced exposure to sunlight. It seems that in places with high humidity and a sultry climate, exposure to sunlight in summer can be low too. This study was designed to determine the vitamin D deficiency prevalence in Sari, a city with a high humidity climate at the end of summer, and compare it to winter. Material and methods: This cross-sectional study was carried out on men and women aged 10 to 70. Clustered blood samples were received from 351 subjects who participated in this study toward the end of summer, and in winter. The levels of serum vitamin D, calcium, phosphorus, alkaline phosphatase and PTH were measured. T test and X2 were used for data analysis. Results: 351subjects (66.4% women, 33.6% men) aged 11 to 69 (mean age ± SD 37.11 ± 12.6) participated in the study.

The mean 25-(OH) D concentration in

• summer was 13.41 ± 13, and in

• winter it was 11.7 ± 11,

and the difference was statistically significant (p ? 0.02).

The prevalence of 25-OHvitamin D deficiency was

• 87.5% (307) in winter and

• 78.6% (276) in summer (p ? 0.05).

Conclusion: This study shows that although in this area with a high humidity climate, seasonal variation of vitamin D is statistically significant, the prevalence of Vitamin D insufficiency is as high in summer as in winter.

PMID: 21717408

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We guess that it is not nearly so sever in countryside, which has

• Fewer clothing restrictions

• Far less haze

• Less air conditioning

See also Vitamin D Life

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• 23 ng of vitamin D in sunny Israel – Dec 2010

• High Prevalence of Vitamin D Insufficiency in Athletes and Dancers in Israel

• Ultra-orthodox jews also suffer from 10 ng vitamin D levels – Nov 2010 clothing restricts access to the sun

• Arab pre-term infants often have less than 10 ng of vitamin D - 2010

• Air Conditioning probably has decreased vitamin D from a book

• Doubling of people less than 30 ng of vitamin D - 75% of whites and 90% of blacks – Feb 2010

• Even in Sunny Areas, Vitamin D Intake Often Too Low - May 2010

• Less than 4 ng is more common in Saudis than diabetic Saudis – July 2010

• Parkinson disease increased in Israel by 50 percent in 7 years – June 2011

• Hypothesis – China air conditioning disease is the result of less vitamin D – March 2011

• Red Alert – one in three pre-teens in Tehran had less than 5 ng of vitamin D – Feb 2011

• Diabetes rising quickly in areas with recent air conditioning – June 2011