Researchers analyzed the responses of more than 18,000 Americans from a seven-year nutrition survey and found that, compared to normal-weight individuals, obese adults had 5 to 12% lower intakes of all micronutrients across the board. A few specific deficiencies stood out, too: Compared to normal-weight adults, 20% more obese adults were lacking in vitamin A, vitamin C, and magnesium. They were also less likely to meet recommended federal requirements for calcium, vitamin D, and vitamin E. What’s behind this shortfall? One explanation is that people with higher BMIs simply tend to eat foods with fewer nutrients. But the study authors also entertain a different possibility: Inadequate nutrient intake may actually contribute to obesity. Vitamin A, the paper notes, is linked to regulation of fat cells and the hormones they release—and could play a role in maintaining healthy body weight. And vitamin D may play a role in the release of leptin, the hormone that controls our sense hunger and how much fat is stored in the body. Not getting enough of either could have an impact on our body weight. Worried whether you’re getting enough? You should be: The analysis also showed that 40% of all adults, regardless of weight, weren’t consuming recommended amounts of vitamins A, C, D, E, calcium, and magnesium. To see how much you need of these important nutrients, click here. Here’s how to get your full daily needs in one swoop: MORE: The 10 Worst Things That Can Happen When You Don’t Get Enough Vitamin D