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Vitamin D deficiency can result from inadequate exposure to sunlight; malabsorption; accelerated catabolism from certain medications; and, in infants, the minimal amount of vitamin D found in breast milk. In children, vitamin D deficiency can result in rickets, which presents as bowing of the legs; in adults, it results in osteomalacia, which presents as a poorly mineralised skeletal matrix.

A 2011 paper published in the Journal of Clinical Endocrinology and Metabolism aimed to provide guidelines to clinicians for the evaluation, treatment, and prevention of vitamin D deficiency.

“Considering that vitamin D deficiency is very common in all age groups and that few foods contain vitamin D, the Task Force recommended supplementation at suggested daily intake and tolerable upper limit levels, depending on age and clinical circumstances,” the authors concluded.

Most dietary sources of vitamin D do not contain sufficient amounts of vitamin D to satisfy daily requirements – for example, 8 oz of fortified milk (8 oz) contains 100 IU; a serving of fortified cereal, 40-80 IU; and, a tablet of most multivitamins, 400 IU.  Adults and children older than 1-year-old at risk of deficiency require at least 600 IU/day.

Unprotected sun exposure is the major source of vitamin D for both children and adults. The provision of vitamin D from sunlight is as follows:

• Sensible sun exposure, especially between the hours of 10 am and 3 pm, produces vitamin D in the skin that may last twice as long in the blood compared with ingested vitamin D.
• Full-body sun exposure producing slight pinkness in light-skinned persons results in vitamin D production equivalent to ingesting 10,000-25,000 IU.
• Increased skin pigmentation, ageing, and sunscreen use reduce the skin’s vitamin D3 production.

Recommended dietary intake of vitamin D for patients at risk of vitamin D deficiency is as follows :

• In infants and children up to 1 year old, at least 400 IU/day, to maximise bone health.
• In children and adolescents 1-18 years of age, at least 600 IU/day to maximise bone health.
• In adults 19-50 years of age, at least 600 IU/day to maximise bone health and muscle function.
• Raising the serum 25(OH)D level consistently above 30 ng/mL may require vitamin D intake of at least 1000 IU/day.

Whether recommended levels of vitamin D intake will provide all the potential non-skeletal health benefits associated with vitamin D is currently unknown, Medscape wrote.

Medscape’s article ‘Vitamin D Deficiency and Related Disorders’ summarises information on how vitamin D deficiency can be clinically diagnosed and treated. Read the full article HERE.