25/06/2014 10:47 BST | Updated 24/08/2014 06:59 BST

The Two Vitamins That Could Unlock Healthy Aging

We're living longer. In just the last two decades, average life expectancy has risen by four years. But living longer doesn't necessarily mean living healthier: half of these extra years of life are marred by pain and trips to the doctor due to chronic conditions like diabetes, cancer, joint pain, asthma, osteoporosis, stroke and heart disease.

The leading risk factors for chronic disease--such as dietary risks, high blood pressure and high body-mass index--are related to nutrition. And there is a growing body of scientific evidence pointing to the role of vitamins and minerals (together known as micronutrients) in preventing chronic disease. Our bodies need these essential nutrients in small quantities in order to function and stay healthy.

One vitamin in particular is emerging as critical to healthy aging: vitamin E. Another is vitamin D.

A recent study published in the Journal of the American Medical Association and reported in the New York Times found that vitamin E slowed the decline of people with Alzheimer's by six months. This means that the people with Alzheimer's who took vitamin E were able to perform basic tasks, like dressing and feeding themselves, longer. They required two fewer hours of help from caregivers each day, compared to the study participants who did not take vitamin E. Additional studies have found that vitamin E may also play a role in the prevention of other neurodegenerative diseases, such as Parkinson's.

Not only can vitamin E help our minds, it helps our bodies. Vitamin E is a powerful antioxidant important for the health and proper functioning of all body cells, tissues and organs. It contributes to healthy blood flow by regulating the opening of blood vessels and preventing cholesterol from building up on blood vessel walls. It also helps to maintain the immune system, especially among seniors.

Yet more than 90% of Americans do not get enough vitamin E.

And more than 75% of Americans are low in vitamin D, the other vitamin key for seniors' health.

You're probably more familiar with the health benefits of vitamin D. It helps bones absorb calcium, and improves muscle strength, preventing falls and fractures. Among people over age 50, one in three women and one in five men experience bone fractures linked to inadequate vitamin D. Proper vitamin D intake could reduce such fractures by 28 percent. Vitamin D is also known to lower blood pressure, strengthen the immune system and reduce the risk of multiple sclerosis, diabetes, stroke, heart attack and heart failure, depression and Alzheimer's.

So how can we make sure to get enough of these vital nutrients?

Though vitamin E can be found in foods like dairy products, vegetable oils, nuts and whole grains, it is difficult to get the recommended daily amount of vitamin E through diet. Vitamin D can be found in fish liver oils, meat, dairy products and eggs, but the main source is sunlight. The vitamin is produced in the body when skin is hit by sunlight. Because the body's ability to produce vitamin D decreases with age, seniors are at risk of vitamin D deficiency. Also at risk are people living north of 40 degrees latitude--that's everyone in the US north of Chico, Denver, Kansas City and Philadelphia.

As a professor of healthy aging, my work focuses on how we can all enjoy our longer lives. The evidence is clear: essential nutrients, including vitamins, are necessary for optimal health. One way you can protect your health is to be aware of your vitamin D and E intake. Get your vitamin levels tested at your next checkup. Make sure you're getting the recommended amounts of vitamin D and E, whether through diet, vitamin supplements or both.

Because in our later years of life, we should be focusing on our next visit to see the grandchildren, not the doctor.