Get gorgeous via a pill? If only it were that easy! “Supplements can’t take the place of a wholesome, colorful diet filled with good-for-you foods like fruits, vegetables and whole grains,” says Kristin Kirkpatrick, R.D., M.S., Wellness Manager for Cleveland Clinic’s Lifestyle 180 program, and YouBeauty Nutrition Advisor. But even on your most perfect eating days, there might be a few things missing.Luckily, research has shown some promising benefits of certain vitamins and supplements to give you a beauty boost, from the inside out. Here are the top contenders:For Healthy Hair & Strong NailsTry BiotinWhy Results from several small studies suggest that biotin supplements may improve brittle nails and thinning hair. Less commonly known as vitamin H, biotin is part of the B complex vitamins, which help your body metabolize fats and protein. Some experts, like Amy Wechsler, M.D., YouBeauty Dermatology Advisor, recommend a daily supplement for everyone. “Biotin promotes the healthy growth of nails more so than hair but it does help with both, so I suggest five milligrams per day,” says Wechsler.FYI Biotin is generally safe and probably hard to get too much of, says Maria Colavincenzo, M.D., assistant professor of dermatology at Northwestern University’s Feinberg School of Medicine.One to try Nature’s Bounty Biotin 1000 mcg, $10QUIZ: How Healthy Does Your Hair Look? For Younger-Looking SkinTry Vitamin DWhy There’s little evidence that vitamin D (aka the “sunshine vitamin”) taken in supplement form directly improves your skin’s appearance. However, “the sun is your skin’s biggest enemy in terms of wrinkles and age spots,” says Colavincenzo. So, getting your D from diet (it’s found in foods like salmon and mackerel, cheese and egg yolks) and supplements, rather than direct sunlight, is a safer way to get the benefits of D and keep your skin young. The Institute of Medicine of the National Academies currently recommends 600 IU per day, but some experts feel that’s too low and suggest a higher daily intake closer to 1,000 IU.FYI Buy D3, rather than D2. Vitamin D3 (cholecalciferol) is the type your body makes when exposed to sunlight. “It’s the only effective form you can take orally,” says Esther Blum, R.D., author of “Eat, Drink and Be Gorgeous.”One to try NatureMade Vitamin D 1000 I.U, $11QUIZ: What’s Your Best Skincare Routine?For a Blemish-Free FaceTry ProbioticsWhy Small studies suggest that oral probiotics (live microorganisms similar to those found in your gut) might help combat acne by reducing inflammation and oxidative stress (internal damage caused by free radicals). A recent report from the State University of New York Downstate Medical Center and the Integrative Care Centre of Toronto analyzed the available research and concluded that there is convincing evidence to suggest that gut microbes, and the quality of the gastrointestinal tract, contribute to the development of acne. Think of your skin as your intestines turned inside out; what’s going on with your skin is a direct reflection of what’s going on digestively, says Blum. “Stress, sugar, booze and birth control pills can all disrupt the natural ecosystem of your intestinal tract.”FYI Check for a mix of lacto and bifido bacteria on the bottle and make sure you’re buying a high-quality probiotic that’s still live because some retailers keep them on store shelves long after their expiration date, which provides zero benefit, says Blum.One to try Sustenex Daily Probiotic, $13OPINION: Prenatal Vitamins Prevent Autism and Bolster BeautyFor Better MoodTry Omega-3sWhy “Evidence suggests that omega-3 fatty acids have some mood elevating effect,” says David Rakel, M.D., director of the University of Wisconsin Integrative Medicine program. A Canadian study of over 400 adults with major depression found that those who took a fish oil supplement for eight weeks showed improvement in their moods compared to those who took a placebo. Fish oil may also help healthy adults without depression as well. Research from the University of Pittsburgh School of Medicine analyzed levels of omega fatty acids in 116 people and found that those with lower amounts in the blood were more likely to report negative mood and affect.FYI Look for a higher ratio of EPA to DHA (7 to 1 is ideal) on the ingredient list, which works better for mood. And store fish oil in your fridge. “It’s a polyunsaturated fat that spoils easily so keeping it in a cool environment will prolong its life,” says Rakel. For a vegetarian option, go for DHA sourced from algae.One to try Eskimo-3 Integrative Therapeutics Natural Stable Fish Oil, $16, or Life’s DHA All-Vegetarian DHA Supplement, $35For Less StressTry Vitamin CWhy Some research has found that high intakes of vitamin C help ease stress levels. One study found that participants who took 3,000 mg per day had lower blood pressure and symptoms of perceived stress compared to those who took a placebo. “Vitamin C blunts the effects of cortisol, a stress hormone released by the adrenal glands,” says Blum. The recommended dietary allowance of vitamin C is 75 mg (much lower than the amounts used in most stress-related research!) so it’s still a good idea to speak to your doctor or nutritionist before starting a supplement.FYI Humans can’t store vitamin C in the body (it’s a water-soluble vitamin, which means that any excess your body doesn’t use is excreted), so we have to get it orally through supplements and vitamin C-rich fruits (like oranges and strawberries) and vegetables (such as broccoli) on a daily basis, says Blum.One to try NatureMade Vitamin C Liquid Softgel 500 mg, $10For Crystal VisionTry B-Complex Vitamins.Why To keep your eyesight strong, B vitamins might be the answer. A study from Harvard’s Brigham and Women’s Hospital randomly assigned over 5,000 women with pre-existing cardiovascular disease or at least three risk factors to take either a combination of folic acid, vitamin B6 and B12 or a placebo. After seven years, those who took the B combo significantly reduced their risk of macular degeneration (a retina disease that causes blurred vision and can lead to blindness).FYI If you’re already low in these water-soluble vitamins (found in food sources like dark green leafy vegetables and animal protein), more energy might be an added bonus of supplements. “The B vitamins are very important for energy production and a deficiency can result in fatigue and less stamina,” says Rakel.DISCUSS:What Supplements Should I Take?For Clear ThinkingTry Vitamin DWhy Low levels might affect your brain functioning; another reason to take your D. A study of over 5,500 French women found that inadequate weekly intakes (less than 35 mcg or 1400 IU) were associated with cognitive impairment, and lower scores on mental tests. Although researchers didn’t prove a cause and effect relationship between vitamin D intake and increased cognition, it’s something to keep in mind (no pun intended!). FYI You can get your D levels checked with a quick blood test at your doc’s office, and then discuss with your health care professional how much you should supplement. “Vitamin D is, across the board, the most common vitamin people are lacking,” says Kirkpatrick.One to try NatureMade Vitamin D 1000 I.U, $11Smart ShoppingIf you find the supplement aisle completely overwhelming (so many different brands, labels and claims!), you’re not alone. Although the supplement industry is a multi-billion dollar business, it’s not held up to the same rigorous clinical study testing required for pharmaceutical meds to hit the market. This means that sometimes a supplement might not actually contain what it says or live up to the claims on the label. Here’s the good news: “You don’t have to spend a lot of money to get a high quality supplement, you just have to be a savvy consumer,” says Paula Gardiner, M.D., M.P.H., assistant professor of family medicine at Boston University Medical Center. A few expert tips:Do your research: Visit consumerlab.com, and search for the brand or general type you’re looking to buy. “This site conducts independent testing on supplements and tests them for efficacy and quality,” says Rakel.Look for quality seals on the label: The USP (US Pharmacopeia) seal and the NSF (NSF International) seal mean that the supplement has gone through independent, third party testing, is safe and contains what it claims. “Anything with either of these seals means it’s a high quality product,” says Gardiner.Consider “whole food” supplements: “When you eat real food, hundreds of chemicals are working synergistically together,” says Gardiner. These supplements try to mimic that effect as closely as possible with a more concentrated formula, rather than just providing the specific vitamin or compound. Are they more effective? The research isn’t there yet, but some experts are hopeful: “They’re put together with more of a natural balance, so I recommend them to patients, ” says Nancy Lonsdorf, M.D., an Ayurvedic doctor and author of “The Ageless Woman: Natural Health and Beauty After Forty with Maharishi Ayurveda.”QUIZ: What’s Your Eating Style?