Vitamin D status and health correlates among apparently healthy participants in an urban, sunny region.
Cent Eur J Public Health. 2012 Dec;20(4):262-9.
Vallianou N, Bountziouka V, Akalestos T, Evangelopoulos A, Vogiatzakis E, Bonou M, Barbetseas J, Avgerinos PC, Panagiotakos DB.
General Hospital of Athens Polykliniki, Athens, Greece. natalia.vallianou at hotmail.com
AIM: To assess vitamin D status and health correlates in a sample of apparently healthy Caucasian participants residing in an urban area, Athens, with latitude 370 58' 0" N and longitude 230 43' 0" E, after taking into consideration a broad range of purported biological, behavioural and environmental factors.
METHOD: Men and women 35+ years from a selected population (n = 490) were studied. Participants completed a detailed questionnaire regarding socio-demographic, lifestyle, clinical and dietary characteristics. Biomarkers were measured after 12 h fasting. Linear and multinomial regression models were used to evaluate the association between 25(OH)D and determinants of vitamin D status.
RESULTS: Results revealed that one hour increase of sunlight exposure decreased the odds of having D deficiency (i.e., < 20 ng/mL) by 70% (OR = 0.30, 95% Cl: 0.20-0.45), adjusted for age, sex, family status, physical activity, smoking habits, BMI, triglycerides, parathyroid hormone, uric acid, haptoglobin, folate acid and haemoglobin, as compared to sufficient levels (i.e., >30 ng/mL). Regarding biomarkers, parathyroid hormone and haptoglobin were found to be related with the odds of having vitamin D deficiency (OR = 1.11, 95% CI: 1.05-1.16; OR = 1.02, 95% CI: 1.00-1.03, respectively) as compared to the sufficient levels.
CONCLUSIONS: Sufficient serum vitamin D levels were observed among participants with characteristics associated with reduced cardiovascular risk, such as normal BMI, increased physical activity, decreased parathyroid hormone and decreased inflammatory markers. Even a slight increase in sunlight exposure could have beneficial effects on serum vitamin D concentrations and eventually on haemoglobin and inflammatory markers levels, thus providing a simple and inexpensive lifestyle intervention that promotes public health.
- Yes, about 1 hour daily sunshine is the minimum needed, vs the 10 minute myth
- abstract does not indicate amount of clothing
- abstract does not indicate skin color – suspect much more needed for those with dark skins
- suspect this study was done during the summer – more time would be needed in other seasons
- latitude of Athens: 38 degrees
- Greek UV Index vs month Jan: 3, Feb: 4, March: 5, April: 8, May: 9. June: 9 July: 10, Aug: 9, Sept: 7, Oct: 4, Nov: 3, Dec: 2
from World Health Organization
- Optimize vitamin D from the sun
- No – 10 minutes per day of sun-UVB is NOT enough
- 5-10 minutes provides only 1,000 IU ONLY IF you are near the equator
- AND young
- AND not obese
- AND have light skin
- AND it is summer
- AND it is the middle of the day
- AND you have lots of skin exposed to the sun
- AND you are lying down
- AND you are not wearing sunscreen
- AND you have a healthy Liver
- AND no clouds and nor air pollution
- AND you have good response to sunshine (4X variation between individuals)