Vitamin D helps the body absorb calcium and is a critical component in the formation of strong bones and teeth. Deficiencies can lead to osteoporosis in adults and rickets in children- the latter of which is charaterized by abnormal bone formations. Too much vitamin D, on the other hand, can lead to serious health problems.
Exposure to sunshine starts a chemical process in the body that allows it to create vitamin D. This is also available in a variety or foods. Some foods include eggs, salmon, tuna and shiitake mushrooms.
Below is a guideline of generalized dosage based on age:
Infants and children 200 IU or 5 mcg/day
Adults ages 19-50 years of age 200 IU or 5 mcg/day
Adults ages 51-70 years of age 400 IU or 10 mcg/day
Adults 71 years or age and older 600 IU or 15 mcg/day