By now, it comes as no surprise that research consistently extols a nutrient-dense diet not only for disease prevention and overall well-being but also for improving your appearance. In fact, a recent analysis from the journal Dermato-Endocrinology deemed nutrition among the most important factors for skin health. Many of you agree: When we asked Delicious Living readers for top skin-health secrets, you advocated nutrient-dense fruits and veggies and healthy fats as the best defense against dry skin, wrinkles, and more. However, when you’re not getting enough crucial nutrients, the results can show up on the outside. “As with many things, symptoms of nutrient deficiencies frequently appear on your skin, nails, and hair,” says Amy Wechsler, MD, a New York City–based dermatologist and author of The Mind-Beauty Connection (Free Press, 2008). To pinpoint common deficits, book an appointment with your mirror and look for these signs, which can indicate unexpected dietary imbalances as well as more serious health issues.

Deep wrinkles.

Everyone gets wrinkles, whether from sun exposure, eating too many processed foods, or aging. But research from the Yale School of Medicine shows that deeper wrinkles may also indicate lower bone density, which increases fracture risk. The reason: Skin and bones share the same building block proteins, including collagen, which keeps skin taut and wrinkle-free.

  • The fix: Take 2,000 mg collagen (including types I and III) daily and eat foods containing lysine, an amino acid that helps your body build collagen and absorb calcium. Lysine-rich foods include fish, egg whites, and legumes. For overall skin health and wrinkle prevention, also opt for free radical–fighting fruits and vegetables, along with healthy oils such as olive oil and flaxseed oil.

Lackluster complexion.

Skin pallor could signal various concerns, including anemia or hypothyroidism (underactive thyroid). If you have hypothyroidism you also may notice yellowish skin or orange palms and soles, thought to result from impaired conversion of beta-carotene to vitamin A.

  • The fix: If anemia is causing your pallor, your medical practitioner will check your levels of vitamins B6, B12, B9 (folate), iron, and vitamin C; deficiencies may require large-dose treatments to get you back on track. If hypothyroidism is the culprit, as part of a comprehensive thyroid-stabilizing diet you’ll want to incorporate vitamin D (1,000–2,000 IU daily), iron (15–30 mg elemental iron daily), and selenium (400 mcg daily). Also eat plenty of lightly cooked brassica and cruciferous vegetables such as Brussels sprouts, cabbage, and broccoli, which help balance thyroid hormones and are filled with cancer-fighting phytochemicals and fiber (but eaten raw, they can actually exacerbate the problem).