Vitamin D plays an important role in the human body, especially for healthy bones. If a person suffers from vitamin D deficiency, this can promote osteoporosis and increase the risk of dementia. The body produces 90 % of the required vitamin D with the help of daylight. The remaining 10 % is ideally supplied by our diet. The highest content of the vitamin is found in fatty fish such as salmon. Eggs and some mushrooms also contain vitamin D.

Julia Kühn, University of Halle-Wittenberg, Germany, and colleagues have found that cocoa is another Vitamin D source. Cocoa beans are usually dried in the sun for one to two weeks after fermentation. The researchers hypothesized that a precursor of the vitamin (ergosterol) is converted into vitamin D₂ in the process.

Using mass spectrometry (MS), the team found that the vitamin D₂ content varies greatly from food to food. High levels were found for cocoa butter and dark chocolate (1.90–5.48 µg/100 g), while white chocolate has low levels of vitamin D₂ (0.19–1.91 µg/100 g).

The scientists aim to investigate whether sugar-free, cocoa-containing foods, e.g., pasta, could be produced and contribute to improved vitamin D₂ levels in humans. Eating large amounts of chocolate to meet the daily need for vitamin D would be extremely unhealthy because of the high sugar and fat content.

• Cocoa and chocolate are sources of vitamin D₂,
  Julia Kühn, Annett Schröter, Bernd M. Hartmann, Gabriele I. Stangl,
  Food Chem. 2018, 269, 318–320.
  https://doi.org/10.1016/j.foodchem.2018.06.098