Magazine article The Exceptional Parent

Optimal Intakes of Vitamin D for Persons with Intellectual Developmental Disabilities: Sunlight Isn't Enough: Almost Everyone Needs Vitamin D Supplements

Magazine article The Exceptional Parent

Optimal Intakes of Vitamin D for Persons with Intellectual Developmental Disabilities: Sunlight Isn't Enough: Almost Everyone Needs Vitamin D Supplements

Article excerpt

Adequate vitamin D is essential for optimal health. In addition to the well-known effects of enhancing mineral metabolism, irrespective of the age, gender, or health status of the patient, vitamin D has beneficial effects on many other conditions, including neuromodulation, muscle strength and coordination, autoimmune disorders, cardiovascular systems, pancreas, muscles, brain, controlling infections, and certain forms of cancer. Yet, vitamin D deficiency is the most common nutritional deficiency in the world. Prevalence of vitamin D deficiency is high in children in general, and it is alarmingly high among people with intellectual developmental disabilities (PIDD or PID). Moreover, many medications commonly taken by people with ID, as well as by those with medically complex developmental disabilities (MCDD), further decrease blood vitamin D levels, requiring them to take higher amounts of vitamin D.

The best way to determine vitamin D status is to measure blood levels of 25-hydroxyvitamin D [25(OH)D]. Since there is no apparent toxicity with levels below 100 ng/mL, the American Endocrine Society's recommends a normal range 30 to100 ng/mL, with a preferred range of 40 to 60 ng/mL. Based on the currently accepted minimum levels of vitamin D in "healthy" people, approximately 80 percent of persons with MCDD are vitamin D insufficient [serum 25(OH)D levels below 30 ng/mL], and more than 50 percent are vitamin D deficient [serum 25(OH)D levels below 20 ng/mL].

New guidelines for vitamin D address the fundamental issues of identifying specific populations at risk for vitamin D deficiency, their major health concerns, and how to treat them without adverse effects. Meanwhile, poor diets, long-term use of gastric acid-reducing agents (proton-pump inhibitors, or PPIs), and celiac disease, all reduce vitamin D status and thus calcium absorption. When calcium is deficient, active vitamin D [1,25(OH)2D, which is in fact, a hormone] starts to rob calcium from bones to maintain normal blood calcium levels. Thus, both adequate calcium and vitamin D nutrition are important.

For "healthy" people, the minimum level of serum 25(OH)D level required for optimal health appears to be 30 ng/mL (75 nmol/L) and the optimum range, 30 to 50 ng/mL. However, for special populations, such as institutionalized persons, PIDs, those with MCDD, and anyone receiving certain medications, such as anti-epileptic or psychotropic agents, a minimum level of 40 ng/mL (100 nmol/L) with the optimal range between 40 to 60 ng/mL is recommended. For most PIDD, this requires a daily vitamin D intake of between 2,000 and 4,000 International Units (IU) or taking 50,000 IU twice a month. The cost of this is only $10 to $15, per patient, per year.

PIDDs who reside in developmental disability centers routinely receive between 400 and 600 IU of vitamin D a day. However, at these low doses, only a very few of the residents will maintain healthy blood vitamin D levels. Suboptimal blood vitamin D status are common among certain other groups, including the obese, those with impaired gastrointestinal absorption of vitamin D, those taking anti-epileptic or psychotropic agents, and institutionalized persons, such as those in nursing homes, group homes, and developmental disability centers (less sun exposure). These groups of people require higher doses of oral vitamin D to maintain healthy serum vitamin D levels. However, a sensible and adequate sun exposure and an improved dietary and supplemental vitamin D intake prevent this global health issue.


There are four main causes of vitamin D deficiency: (A) lack of adequate skin exposure to sunlight (Note: less sun exposure is in part attributable to skin color and clothing cover, concerns about skin cancer, climatic changes and atmospheric pollution, etc.), (B) less-than-adequate dietary intake (e.g., vegetarianism; other than fatty-fish, diet contain only little amounts of vitamin D), (C) enhanced catabolism of vitamin D (due to medications, especially glucocorticoids and anti-seizure medications), and (D) co-existing number of other diseases as described above. …

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