Vitamin and mineral requirements

During adolescence, not only do energy and protein needs increase, but also the requirements for vitamins and minerals involved in energy metabolism and growth processes.

Vitamin requirements

Vitamin b1 (thiamine), vitamin b2 (riboflavin), vitamin b3 (niacin). As a consequence of the high energetic requirements during adolescence, the requirements of vitamins b1, b2, and b3 are higher, since they intervene in the metabolism of carbohydrates. Foods containing these vitamins are:

• Foods containing vitamin b-1: rice, wheat, corn; mushrooms, nuts, legumes, vegetables and fresh fruits; meats, fish, offal, eggs and dairy products.

• Foods containing vitamin b-2: dairy products, meats, liver, eggs and nuts.

• Foods containing vitamin b-3: meats, fish, milk and eggs; cereals and nuts.

Vitamin b6 (pyridoxine), vitamin b9 (folic acid), vitamin b12 (cobalamin) The demands for vitamins b6, b9 and b12 are also higher, as they are necessary for the normal synthesis of DNA and RNA, necessary for protein metabolism, which increases throughout adolescence.

Adequate amounts of folic acid are recommended, especially in girls. It is very important the intake of this nutrient throughout the fertile period of women, its deficiencies are associated with births of children with neural tube closure defects, such as spina bifida.

Foods containing these vitamins are:

• Foods containing vitamin b-6: liver, meats, fish, legumes and nuts.

• Foods containing vitamin b-9 (folic acid): animal viscera, green leafy vegetables (spinach and chard), legumes, nuts; whole grains, such as almonds; and in fortified foods. It should be taken into account that folic acid is very difficult to supply as it is easily destroyed by heat and oxygen, so the intake of fortified breakfast cereals is recommended.

• Foods containing vitamin b-12: they are found only in foods of animal origin. The most important source is liver, although it is also found in kidney, meat, eggs, dairy products and oily fish.

Vitamin a and vitamin d: Adolescence, being a period of rapid growth, requires increased amounts of vitamin a and d, which are necessary to maintain the structure and function of new cells. Vitamin a is essential for the transport of iron in the tissues. Vitamin d is necessary to support bone growth together with calcium. Foods containing these vitamins are:

• Foods containing vitamin a: beef, pork, turkey and chicken liver; fish, eggs and milk; spinach, carrots, parsley, broccoli leaves, pumpkin and sweet potato.

• Sources of vitamin d: it is obtained fundamentally by cutaneous synthesis, mediated by ultraviolet radiation from the sun. It can also be obtained in some foods such as egg yolk, liver, dairy products and fatty fish.

Vitamin c (ascorbic acid) and vitamin e: To maintain the structural and functional normality of new cells during adolescence, higher amounts of vitamins c, a and e are required. Foods containing these vitamins are:

• Foods containing vitamin c: in fruits such as kiwi, lemon, tangerine, orange, grapefruit and guava; in vegetables such as lettuce, spinach, broccoli, tomato, bell pepper, carrot, cauliflower and cabbage.

• Foods containing vitamin e: eggs, nuts, olives, seed oils such as sunflower and corn; in green leafy vegetable foods such as broccoli and spinach.

Mineral needs

Calcium: Among the most demanded minerals during adolescence is calcium, which is necessary for growth and bone mineralization. The peak of demand occurs in girls around 13 years of age, while in boys it occurs around 15 years of age, coinciding in both cases with peaks in the speed of growth.

To ensure adequate calcium intake, adolescents should drink three to four daily servings of milk or milk products. Dairy products are rich in calcium and also provide phosphorus in a proportion equivalent to that of bone. Sesame seeds, almonds, hazelnuts and legumes also contain calcium.

The recommended daily intake of calcium in the period of adolescence for the Spanish population in both sexes is 1300 milligrams per day.

Calcium deficiencies can cause inadequate ossification, increasing the risk of osteoporosis later in life. This disorder is more frequent especially in women during postmenopause, causing fractures or micro fractures due to blows or falls.

Iron: Increased iron intakes in adolescence are justified for three main reasons:

• Incre