Calculation of the Sun exposure time for the synthesis of vitamin D in Urcuqu\'i, Ecuador

TL;DR

This study calculates vitamin D and erythemal irradiances in Urcuqu'i, Ecuador, revealing that using erythemal irradiance overestimates sun exposure time needed for vitamin D synthesis by nearly 100%.

Contribution

It introduces a spectral solar irradiance-based method to accurately determine vitamin D synthesis exposure times, improving upon previous erythemal irradiance estimates.

Findings

Erythemal irradiance overestimates vitamin D exposure time by nearly 100%.

Spectral irradiance provides more accurate vitamin D synthesis calculations.

Minimal exposure times vary significantly depending on irradiance type.

Abstract

The synthesis of vitamin D is strongly linked to the availability of solar energy. For a long time, it was clear that using the erythemal irradiances is a good choice to calculate the exposure time. Several authors argue that this method of minimum exposure time overestimates the calculation of the solar irradiance of vitamin D. In this paper, the vitamin D and erythemal irradiances are calculated on the basis of the spectral solar irradiance in Urcuqu\'i (Ecuador). From these results, we obtain the minimal exposure time. It was found that there is a difference between the use of the erythemal irradiance and the vitamin D one; namely, the exposure times were too large (almost a 100% difference) for the erythemal irradiance.