Dermatologists use sun block, stay indoors, and have low vitamin D (Thai in this study)
Vitamin D status in Thai dermatologists and working‐age Thai population
The Journal of Dermatology https://doi.org/10.1111/1346-8138.14742
Natta Rajatanavin Silada Kanokrangsee Wichai Aekplakorn
| Thai | Thai dermatologists | |
| Sufficiency (>30 ng/mL) | 31 % | 0 % |
| Insufficiency (20–30 ng/mL) | 50 % | 39 % |
| Deficiency (<20 ng/mL) | 18 % | 60 % |
| Severe deficiency (<10 ng/mL) | 1% | 1% |

This study aimed to determine the prevalence of vitamin D insufficiency among Thai dermatologists compared with the general working‐age population in Bangkok. A cross‐sectional study was conducted in healthy Thai physicians who had at least 1 years’ experience in dermatology practise and a subsample of the general Thai population from the Fourth National Health Survey. Serum 25‐hydroxyvitamin D (25[OH]D), a combination of 25(OH)D2 and 25(OH)D3, levels in both groups were measured using liquid chromatography coupled with mass spectrometry. The majority of dermatologists were of Fitzpatrick skin type III (n = 61, 61.3%) or IV (n = 32, 33.3%).
The mean serum 25(OH)D and 25(OH)D3 levels were 18.9 and 18.2 ng/mL, respectively,
whereas the corresponding levels in the general population were 26.5 and 25.8 ng/mL.
None of the dermatologist had serum 25(OH)D sufficiency (>30 ng/mL),
38 (38.78%) had vitamin D insufficiency (20–30 ng/mL) and
60 (61.22%) had vitamin D deficiency (<20 ng/mL).
The frequency of vitamin D deficiency in dermatologists was significantly higher than in the general population
- (61.2% vs 19.2%, P < 0.001).
Ninety percent of dermatologists used sunscreen daily and spent time mostly indoors.
Dermatologists used physical sun‐protection more than half of the time when outdoors, for example, a
book or paper as a sunshade (70.3%)
an umbrella (48.4%)
a long‐sleeved shirt (20.4%) or a
hat (9.7%) .
In conclusion, dermatologists showed a remarkably high prevalence of vitamin D deficiency which may be due to inadequate exposure to sunlight, regular use of sunscreen and practicing various sun‐protection activities.