B12: Like folic acid, B12 is essential for healthy nervous system development and function. Pregnant women who are vegans or vegetarians may fall short on B12, since it is present in animal protein and to a lesser extent in dairy. Teenage and adult women need 2.4 mcg. Recommended levels rise to 2.6 mcg for pregnant women and 2.8 mcg for lactating women.
Even if you are the most independent exerciser around, give a group fitness class a shot at least once a week—you may find that you enjoy it more than sweating solo. “Happiness and health are shared through social connectedness and closeness,” says Greg Chertok, director of sport psychology at the Physical Medicine and Rehabilitation Center in New Jersey. “Geography and proximity are predictors of how contagious emotions can be, and this may translate into an athletic environment too.” Sign up for Bikram, CrossFit, spin, or Zumba, and you could find yourself—gasp!—smiling at the gym thanks to your classmates.
Young adults. Teen girls and young women usually need more calories than when they were younger, to support their growing and developing bodies. After about age 25, a woman’s resting metabolism (the number of calories her body needs to sustain itself at rest) goes down. To maintain a healthy weight after age 25, women need to gradually reduce their calories and increase their physical activity.
In the past, women have often tried to make up deficits in their diet though the use of vitamins and supplements. However, while supplements can be a useful safeguard against occasional nutrient shortfalls, they can’t compensate for an unbalanced or unhealthy diet. To ensure you get all the nutrients you need from the food you eat, try to aim for a diet rich in fruit, vegetables, quality protein, healthy fats, and low in processed, fried, and sugary foods.