The humble mushroom can pack a powerful nutritional punch, according to two new studies. The edible fungus can help dieters reduce their intake of red meat and still feel full, and can provide as much vitamin D as a nutritional supplement.

Researchers at the Johns Hopkins Bloomberg School of Public Health gave one group of obese adults about one-quarter of a liter of white button mushrooms per day in place of meat. A second group was placed on a standard weight reduction diet.

At the end of a year-long trial, the mushroom group lost more pounds and maintained their weight loss better than the control group. The findings show the benefit of substituting low-energy-density foods, like mushrooms, for high-energy-density foods, like lean ground beef, for reducing energy and fat intake.

In a separate study, at Boston University School of Medicine, researchers randomly gave a small group of healthy adults supplements of either vitamin D2, vitamin D3 or mushroom powder containing vitamin D2 for 12 weeks during the winter. The vitamin, which is crucial for bone health, muscle strength and immune system function, is produced naturally in our skin when exposed to the sun.

At the end of the trial, there was no difference in levels of vitamin D among the three groups. The investigators say their results show that mushrooms are a good natural food source for this important nutrient.