Nutrition Across the Life Cycle

The relative importance of each of the essential vitamins and minerals a body needs for optimal health depends on many factors and varies across the life cycle. In fact, the National Academy of Sciences publishes Dietary Reference Intake recommendations for how much of each nutrient a person should get per day (commonly known as RDAs) that are specific to various stages of life and gender.

Always consult your doctor before you take any supplements. And remember that dietary supplements are not intended to treat, diagnose, mitigate, prevent, or cure disease.

Adolescence and Adulthood

While adolescents and youth need all the same nutrients as healthy adults, the specific amount needed for optimal health is adjusted to address specific issues concerning this particular time in life.

Growth spurts and puberty can spur a surge in appetite for adolescents, requiring an intake of more calories. Foods high in nutritional value, such as fruits and vegetables, dairy, seafood, lean meat, poultry, and eggs should be emphasized to nourish this growth.
Some studies have shown that adolescents are at risk for a deficiency in vitamin D. Vitamin D deficiencies are due to inadequate dietary intake, less sun exposure (less time spent outdoors), or sunscreen usage to protect skin (rays from the sun on the skin cause it to make vitamin D). The main source of vitamin D in foods is fortified foods such as milk, cereal, orange juice, and yogurt.
Calcium is essential for healthy bone building. Adolescent girls do not get enough calcium from their diet alone. Good food sources for calcium include dairy and foods fortified with calcium.
Growth spurts in adolescent and preadolescent boys and girls increase the requirement for iron. Additionally adolescent girls who have started menstruating need even more iron. Dietary iron should mainly come from food sources that contain heme iron, which is the type of iron that body can absorb best and is obtained from meat, poultry, and fish.

For adults 19 to 50 years of age, vitamin and mineral requirements are slightly different in men and women largely due to differences in the body (e.g., bone, muscle tissue, fluid and fat). For example, men tend to be larger in stature and more muscular in physique. Women typically have more body fat in proportion to muscle than men do. For this and other physiological reasons, recommendations for certain nutrients are different between adult men and women.

Men require more of vitamins A, C, K, B1, B2, B3 and choline; and the minerals magnesium, zinc, chromium, and manganese.
Women require more iron to replace this essential mineral that is lost through menstruation. Good sources of iron include lean beef, turkey, chicken, and fish. For those who do not eat meat, a supplement may be a good option to discuss with your doctor.

Women who are Pregnant or Breastfeeding

Women who are pregnant and/or breastfeeding need to ensure they are a eating a well-balanced diet to support a healthy pregnancy and baby. In addition to requiring more calories and protein overall, they also need to pay close attention to getting an appropriate amount of these nutrients:

Vitamin A
Vitamin C
Certain B vitamins, including thiamine, riboflavin, niacin, pantothenic acid, vitamin B6, choline, and vitamin B12
Folic acid to prevent neural tube defects, which should be consumed in adequate amounts prior to conception. Thus the U.S. Public Health Service and the Centers for Disease Control and Prevention (CDC) recommend that all women of childbearing age consume 400 micrograms of folic acid from fortified foods or supplements daily.
- During pregnancy the dietary reference intake recommendation for folic acid increases to 520 micrograms, and then drops down to 450 micrograms during breastfeeding.

Prenatal vitamin-mineral formulas may be suggested by doctors to pregnant women to help them meet these new nutritional needs.

Adults 50+ Years and Older Adults

As we age, our nutritional requirements change with our changing bodies. In fact, as we get older, our calorie needs generally decrease, though our requirement for an adequate intake of vitamins and minerals remains as important as ever, if not more so. Declines in nutrient absorption and kidney function with aging can interfere with adequate nutrition. As adults age, several nutrients are extremely important:

Vitamin D

Increased vitamin D is needed due to the body’s decreased ability to make vitamin D through skin as we age. In fact, the process of aging itself decreases the ability of skin to produce vitamin D in response to sunlight. It can be consumed in fortified milk or other products.

The role of vitamin D in bone health is well established and inadequate vitamin D status can lead to bone health issues. This vitamin is also being studied for its role in a variety of other health conditions. Vitamin D deficiency becomes a bigger problem the older you get, so supplements are often recommended.

Other Nutrients Needed

Other nutrients we need to be sure to get in adequate amounts as we get older include the following:

Calcium is a very important nutrient, especially as we get older. After about age 30, the rate at which we lose bone mass exceeds bone formation. The calcium we take in, therefore, is used to replace the bone we are losing, especially for post-menopausal women, who experience great bone loss during this time.
Dietary fiber in healthy foods goes a long way to help maintain regular bowel function and help you feel fuller.
Zinc deficiency is known to impair taste sensation and given many older adults may experience changes in the ability to absorb zinc in the body (have a reduced ability to absorb zinc), this is a nutrient they need to pay attention to.
Vitamin E is an antioxidant that may help prevent damage to the body’s cells. Research studies are being performed to see if vitamin E can delay or possibly prevent some diseases. It is still not known whether it can prevent heart disease, stroke, cancer or dementia. Vitamin E can be found in whole grains, peanuts, nuts, vegetable oils, and seeds.
Vitamin B12 levels tend to decline with aging and may be due to a decreased ability of the gut to absorb it as we age. Older adults are advised to try and meet this increased need for vitamin B12 by consuming foods fortified with it or by taking a supplement.

For All Ages

No matter your age or place in the life cycle, it is key to try to get as many of the nutrients your body needs through the foods you eat. A renewed emphasis on more plant-based foods such as vegetables, fruit, whole grains, and legumes, with some dairy and lean animal proteins can help to get you closer to this goal. Nutritional intake research continues to find that many people have less-than-perfect diets, which are long on calories/fat and short on essential nutrients. The vast majority of people do not meet all of the recommendations for dietary intake of vitamins and minerals. Therefore, it is recommended that you consult with your health care provider to learn more about your dietary needs.

Alpa V. Shah, MS, RD, CDE is a Senior Medical Manager, US Dietary Supplements, Global Medical Affairs at Pfizer