Vitamin D for Children: Considerations and Recommendations

Vitamin D is an essential hormone, responsible for musculoskeletal development and systemic health. Yet the World Health Organization, the US Institute of Medicine, and the Endocrine Society in the US and Europe acknowledge that vitamin D deficiency is a global public health issue.

A recent clinical study investigated (1) the impact of vitamin D on the developing musculoskeletal system in pediatric patients and a child’s need for nutritional intake or supplementation; (2) factors clinicians need to consider to help parents decide appropriate supplementation for their child; and (3) the risk of overdose of vitamin D.

Vitamin D is unique in its dual absorption mechanism, through both dietary intake and through synthesis by an endogenous process. Fatty fish, fish liver oil, and egg yolks are sources of vitamin D2, while endogenous synthesis produces and absorbs pre-vitamin D3. Well-being of skin, gut, liver, kidney, and bone is vital for vitamin D metabolism.

To answer the study questions, one Cochrane review, two global epidemiological reviews on nutritional rickets, six guidelines on vitamin D supplementation, and several articles on vitamin D and musculoskeletal interaction were consulted.

Among the findings were an increased need for dietary calcium and phosphorus in the 9–18 age group, which faces growth spurts and increased body mass. Inactive children entering competitive sport may be more vulnerable to fracture if bone mineralization is out of balance.  Factors that should be evaluated in determining appropriate pediatric supplementation include exclusive breast feeding, fortified formula, exercise, sun exposure, and dietary habits. Vitamin D supplementation can have adverse effects, including weakness, nausea, loss of appetite, headache, cramps and diarrhea. Overdose is possible, but unlikely.

While recommendations on required dosage varies slightly among organizations, consensus is of 400 IU/day in infancy and early childhood and 600 IU/day for adolescents. Values should be modified based on case history, with anthropometric measurements, diet, exercise, and sun exposure being key considerations. Nutritional rickets can be reduced if supplementation is correct.