Getting the right amount of vitamins on a daily basis helps children grow and develop normally, both physically and cognitively. A 2009 review in “Pediatric Clinics of North America” suggests the most common vitamin deficiency among healthy children is vitamin D.

Children need calcium to build bone tissue, but too much calcium can be harmful. Excess blood calcium, or hypercalcemia, causes the kidneys to work extra hard to remove the overload. Such high levels lead to the formation of kidney stones. Diet alone is not always the culprit of high calcium levels.

If you're the parent of a young child, you might be thinking of enrolling him in a daycare, preschool or pre-kindergarten program to prepare him for elementary school. These programs are typically run by those with early childhood education certification and often offer more than just playtime.

Children may suffer from constipation when hardened stools become difficult or painful to pass. Left untreated, the condition may become chronic, as a child becomes fearful of defecation and holds in his feces.

Bifocals are dual-vision glasses that allow the patient to see two different vision prescriptions through the same lens. Bifocals can often be identified because they look like a normal glasses lens with a portion of another lens resting on top, either in a circular or sliver shape.

As your child enters puberty or adolescence, he might notice the presence of dandruff. Also known as sebhorreic dermatitis, dandruff can leave unsightly white flakes on his shoulders.

Children go through an amazing transformation in the earliest years of their life, from a helpless infant to a walking, talking toddler, and on to reading, critical thinking and advanced social interactions in a school setting.

During early childhood, a parent's attitudes and values can be passed on to the child. During this time their self concept is forming, and can be heavily influenced by their parents, according to Heather Weiss, Founder and Director of the Harvard Family Research Project.

Though occasionally troubling in appearance, most dark spots that appear on a child's skin are harmless. Birthmarks, rashes, exposure to the sun or infections of the skin can cause dark spots to appear.

Most parents have accepted the necessity of placing small children in approved car seats. Once children reach 40 pounds, however, many parents want to ditch the space consuming -- but ultimately safe car seat -- and strap a child directly into an adult seat belt.

Yawning, a normal human activity that also occurs in many animals, affects even in fetuses as early as 11 weeks after conception. Yawns occur involuntarily; a person can’t force themselves to yawn or stop a yawn once it starts. The causes of yawning are not well understood.

Xylitol is a sugarless sweetener that’s gaining popularity as an ingredient in candy, chewing gum and toothpaste. Although xylitol has many potential health benefits, particularly for preventing dental cavities, ingesting large amounts of the sweetener could pose some health risks for children.