
Vitamin D or “sunshine vitamin” is a fat-soluble vitamin that the body needs to absorb and retain calcium and phosphorus. Nutrients that are key to the formation of bones, teeth and muscles. Therefore, vitamin D plays a critical role in the body by fulfilling key functions in reducing inflammation and infections, as well as decreasing the growth of cancer cells, acting in neuromuscular and immune functions, among others.

It is important to mention that the most common way to obtain vitamin D is through its endogenous form once sunlight penetrates the skin and activates the synthesis of this vitamin, being this route considered the main source of vitamin D.

A recent study in Australia aimed to randomly assess the effects of egg consumption on serum 25-(OH)-D (25-hydroxy-vitamin D, considered the most accurate measure of the amount of vitamin D in the body) concentrations during autumn and winter. In this study it was shown that the consumption of 7 eggs per week is a safe, acceptable and effective way to avoid the reduction in serum 25(OH)D concentrations during winter.


HOW TO IMPROVE VITAMIN D LEVELS IN EGGS?
As is well known, the nutritional contribution of eggs is linked to the feed and nutrition the hens receive. Currently, most hen production systems are confined, which makes exposure to direct sunlight difficult to obtain endogenous vitamin D..
Some nutritional strategies for laying hens include the addition of vitamin D analogues as a source of vitamin D.
Briefly, these compounds are intermediate metabolites in the vitamin D absorption process, which are activated when they pass through the liver or kidneys of the birds, thus releasing active vitamin D compounds into the bloodstream, which allows the absorption and other metabolic functions of this vitamin.

HOW MUCH VITAMIN D SHOULD A PERSON CONSUME?
Vitamin D intake can be measured in micrograms (μg) or IU.
The recommended daily intake levels of vitamin D according to the U.S. National Institute of Health are:
