Vitamin D regulates calcium absorption, cell growth, immune functions and inflammation in the body, and researchers are saying that many Americans are simply not getting enough of it. New research has suggested that enriching bread with the nutrient may partially relieve this public health issue.

The key, says a study in the Journal of Agricultural and Food Chemistry, is using strains of yeast that yield larger loads of vitamin D.

Researchers tried feeding vitamin D-enriched bread to laboratory rodents and found that the process had positive results. Those test animals given bread made with yeast that contains more vitamin D2 – a dietary form of the nutrient – absorbed nearly as much as they would if exposed to sunlight, which causes the skin to form vitamin D3.

However, between bread pricing and lack of sunlight during winter, it may be to one’s advantage to take vitamin supplements, many of which are guaranteed to provide the full daily dose of vitamin D.

Multivitamins can supplement even the healthiest diet, since few foods – other than eggs, mushrooms and some fish – naturally contain vitamin D.