Surveys have found that adolescent girls are less likely than adolescent boys to achieve the recommended dietary intakes for calcium. Contrary to what is observed in boys, calcium intake in girls begins to decline around the time of puberty. Declining calcium intakes in teenage girls may be due to an avoidance of milk, a beverage many girls mistakenly believe causes weight gain. However, studies have found that girls who drink milk experience less weight gain and have lower percent body fat than those teens who take calcium supplements. Vitamin D, which promotes the transport of calcium across the intestinal mucosa, is essential for calcium absorption.
Vitamin D is important during adolescence, given the high calcium demands of the teenage years.
Due to the routine supplementation of vitamin D in infancy and childhood, and the fortification of cow's milk with this vitamin, vitamin D deficiency is rarely observed in children in North America. The Impact of Other Nutrients While phosphorous is an important nutrient for bone health, it may have a negative effect on calcium status. High phosphate intakes, particularly in the presence of low calcium levels, have been linked to bone loss in laboratory animals. Preliminary research suggests that excessive consumption of phosphate-containing soft drinks may contribute to low peak bone mass, though the mechanism for this effect is not fully understood. It is possible that these beverages are detrimental to bone health because they are ingested in place of milk.