Vitamins are key factors in keeping our bodies healthy. We find them in both foods and medication. While many are available in pharmacies, only a few are absolutely necessary. We look at six vitamins with the biggest impact on our daily lives.

Vitamin C

Vitamin C is beneficial for repairing body tissues and strengthening the immune system. Orange juice is one of the biggest distributors of this important vitamin. Many people, however, claim that an actual orange can do more than the drink. “People may think it’s less expensive or more convenient to buy a carton of juice, but a whole orange has more vitamin C than a glass of [packaged] juice. Orange growers just don’t advertise oranges — we don’t have the same advertising for any whole food that we do for products,” author Alissa Hamilton told Civil Eats. Aside from oranges, some other foods filled with vitamin C are kale, broccoli, and lemons.

Vitamin E

Vitamin E prevents blood clots from occurring in the body. A recent study by the  Minneapolis VA Health Care System stated vitamin E could weaken Alzheimer’s disease. 600 veterans were split into two groups for this study. One group took a combination of vitamin E and a placebo. The other group took 2,000 international units of alpha-tocopherol, which is a high level of vitamin E. The alpha-tocopherol group saw a sharper decline in the disease’s progression. “It could be very meaningful for someone with early Alzheimer’s who is still functioning at a high level, and for his or her caregivers, to have a delay of six months in the progression of the disease over about a two-year period,” researcher Maurice Dysken said in the study. Vegetable oils, mangos, and peanuts have the biggest offering of vitamin E.

Vitamin A

Vitamin A enhances vision and makes sure the immune system works properly. It also lowers the risk of skin cancer. A study from Brown University analyzed the eating habits of nearly 175,000 people. Individuals with the highest vitamin A intake were 17 percent less likely to have skin cancer. “Skin cancer, including squamous cell carcinoma, is hard to prevent, but this study suggests that eating a healthy diet rich in vitamin A may be a way to reduce your risk, in addition to wearing sunscreen and reducing sun exposure,” Eunyoung Cho said in the study. Foods heavy in vitamin A include eggs, beef liver, and butter.

Vitamin D

Vitamin D helps keep lungs intact and prevents diabetes. In a recent study, nutritionist Kellie Bilinski discovered that many Americans have issues in vitamin D deficiency. “Close to 70% of individuals are vitamin D deficient in spring. Women 20-39 years had the highest prevalence of deficiency. Other risk factors were being from a lower socioeconomic background and living in a major city,” Bilinski told News-Medical. Vitamin D can mostly be found in fish products such as canned tuna, salmon, and herring.

Iron

Without iron, the body won’t be able to produce red blood cells. For centuries, this vitamin has been one of the most important ones in the immune system. Before becoming commonplace in nutrition, Greeks and Romans used it to cure medicinal problems. Turkey, liver, and red meat are among those high in iron. While iron is mainly found in meat, vegetarians can use non-heme iron for their nutritional needs. “Excellent non-heme iron sources include fortified breakfast cereals and white beans. Good non-heme sources include lentils, spinach, firm tofu, kidney beans, chickpeas, tomatoes, potato, and cashews,” Amy Gorin Nutrition owner Amy Gorin told Well & Good.

Calcium

Calcium is crucial in keeping bones and teeth strong. Milk is one of the most popular providers of calcium. “The largest source of dietary calcium for most persons is milk and other dairy products, which accounts for 72% of the calcium in the US food supply,” Frank R. Greer, MD told Pediatrics. Other foods filled with calcium are cheese, yogurt, and beans.