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Nutrition411.qxd:Layout 1 4/2/09 10:29 AM Page 8 Vitamin D Deficiency: Shining New Lighton the Sun Nutrient Nancy Col ins, PhD, RD, LD/N, FAPWCA; and Nancy Spaulding-Albright, MMS, RD, LD/N, CNSD During the past two decades, research on vitamin D has in- screens when outdoors. Sunscreens with a sun protec- creased exponentially. Healthcare practitioners have tion factor (SPF) of 15 block 99% of the UVB rays that learned vitamin D plays a much more important role in dis- ease prevention and well-being than was ever suspected. This • Cultural dress, such as hijabs or burkas worn by Muslim new information comes in stark contrast to behavioral trends.
In the 1980s, sun exposure was demonized and we became an • Limited intake of foods that provide vitamin D, such as indoor society. Because sun exposure is one of the best ways fortified milk, fortified cereal, and fatty fish. Table 1 lists to obtain vitamin D, the lack of sunshine plus zealous use of the vitamin D content of the best food choices and select sunscreen has contributed to a vitamin D-deficient society. Vitamin D deficiency is now regarded as a global health • Living 40º north of the equator. The farther a person problem, but despite an abundance of media attention, many lives from the equator, the less his/her exposure to UVB physicians and their patients remain unaware of the possible rays and the less vitamin D produced by the body; ill effects of vitamin D deficiency. Current estimates are that • Limited use of vitamin D supplements. Typical multivi- 50% to 78% of the population has inadequate stores of vita- tamins do not provide an adequate amount of vitamin min D and the incidence is even greater in high-risk groups, D for optimum health if other sources are not present; such as African Americans and homebound elderly.1 • Dark complexions. Persons with darker complexions (eg, individuals from Africa, East India, and the Caribbean) may require up to six times the amount of Vitamin D actually refers to a pair of inactive precursors sun exposure to form the same amount of vitamin D to a critical hormone. Cholecalciferol, more commonly from the sun as light-skinned or Caucasian people; known as D3, is produced in the skin after exposure to ultra- • Aged skin. In general, people >60 years of age have a violet B light (UVB) or from foods we consume. Ergocalcif- 25% reduction in cutaneous formation of vitamin D.
erol, also known as D2, is produced in plants and enters the Senior citizens who are homebound or in long-term care body through diet. Once D2 and D3 are present in circulation, facilities are at very high risk for vitamin D deficiency; they are bound to vitamin D-binding proteins (VDBP) and • Obesity. Because vitamin D is fat-soluble, it appears to hydroxylated in the liver to form 25-hydroxyvitamin D be sequestered in adipose stores and not released easily (25[OH]D) or calcidiol. A further conversion in the kidney changes the calcidiol to 1,25-dihydroxyvitamin D • Malabsorption disorders, including Crohn’s disease, celiac disease, and cystic fibrosis. Patients who have un- Calcidiol is the main circulating and storage form of vita- dergone gastric bypass surgery for weight loss also are min D in the blood, with a half-life of approximately 3 weeks.
This is the preferred form to evaluate vitamin D status in pa- • Kidney disease. Supplementation of the calcidiol form tients. Because the production of calcitriol is tightly regulated of vitamin D often is started too late in many patients with a half-life of only 4 to 6 hours, its measurement is usually with renal disease. A 20% increase in mortality is seen only of interest in renal disease or primary hyperparathy- • Infants breastfed exclusively who are not receiving a vi- tamin D supplement, unless the mother is on a high dose Numerous risk factors may predispose an individual to vi- • Certain medications that can impair absorption (eg, phenytoin and cholestyramine). Other medications ne- • Limited sun exposure, including constant use of sun- cessitate limited sun exposure because of photosensitiv- This article was not subject to the Ostomy Wound Management peer-review process. Nancy Collins, PhD, RD, LD/N, FAPWCA, is founder and executive directorof RD411.com and Wounds411.com. For the past 20 years, she has served as a consultant to healthcare institutions and as a medico-legal expert to law firmsinvolved in healthcare litigation. Correspondence may be sent to Dr. Collins at NCtheRD@aol.com. Nancy Spaulding-Albright, MMS, RD, LD/N, CNSD, is a con-sultant dietitian in the Mount Dora, FL, area. Nutrition411.qxd:Layout 1 4/2/09 10:29 AM Page 9 ity — for example, amiodarone, tetracyclines, and sul- Table 1. Vitamin D Content of Foods and Supplements Evaluating these risk factors is important for every patient, Vitamin D
because the list of diseases and health problems caused or Content (IU)
worsened by vitamin D deficiency is extensive. This includes rickets, osteoporosis, osteomalacia, frequent bone fractures, frequent falls, muscle pain and weakness, heart disease, con- gestive heart failure, hypertension, diabetes, some types of cancer, fibromyalgia, preeclampsia in pregnancy, autoimmunedisorders such as rheumatoid arthritis and multiple sclerosis, depression, brain development, migraines, flu, pneumonia, tuberculosis, and periodontal disease.
For most adults, the recommended daily adequate intake (AI) is 400 international units (IU). For those >70 years of age, Note: Cod liver oil is not recommended because of its high con-
the current recommendation is 600 IU. Research now is show- tent of active vitamin A, which can harm bone health over time.
ing the inadequacy of these current government recommenda- Retinoic acid also may antagonize the action of vitamin D whenthe ratio is in excess.
tions. The general conclusion is that these amounts areinadequate if not supplemented with sun exposure. Vitamin D researchers have appealed to the government to make changes Lu Z, Chen TC, Zhang A, et al. An evaluation of the vitamin D3 content to both the AI recommendations and the tolerable upper-limit in fish: is the vitamin D content adequate to satisfy the dietary require-ment for vitamin D? J Steroid Biochem Mol Biol. 2007;103(3-5):642– (UL) levels. Researchers want to make these changes a priority for both public health and research reasons.6 b USDA National Nutrient Database for Standard Reference.
c Cannell JJ, Vieth R, Willett W. Cod liver oil, vitamin A toxicity, frequent The Institute of Medicine of the National Academies re- respiratory infections, and the vitamin D deficiency epidemic. Ann Otol cently appointed the next Food and Nutrition Board to estab- Rhinol Laryngol. 2008;117(11):864–870. lish new dietary reference intakes (DRIs) for vitamin D andcalcium.7 This is a time-consuming process considering the Table 2. Vitamin D 25(OH)D Assessment Categoriesa vast number of new studies. Persons with an interest in vita-min D are watching closely to see if the recommendations are Classification
modified based on what we have learned from recent research. Vitamin D toxicity is rarely reported but has occurred. In general, toxicity is associated with quality control problems in either the fortification process or with powdered supplements.
The UL, or the maximum level considered safe set by the gov- ernment, is currently 2,000 IU. It is expected that with the ev-idence supplied by recent research, the level likely will increase Subject to change as research continues. No formal guidelines are setat this time b Serum concentrations of 25(OH)D are reported in both ng/mL and nmol/L. The conversion factor is1 ng/mL = 2.5 nmol/L Serum 25(OH)D levels <15 nanograms (ng)/milliliter (mL) are treated with much higher amounts of vitamin Dthan can be obtained in nonprescription supplements. In Dr. Robert Heaney, a prominent vitamin D researcher, es- order to replete the deficiency quickly, prescription supple- timates that an intake of 3,000 IU (per day) of vitamin D is ments containing 50,000 IU of vitamin D per week for at least needed to bring 95% of the population out of the deficient 8 weeks are suggested.3 After 8 weeks, blood levels are retested range.9 It is important to note that researchers have not iden- to determine if this level of supplementation needs to be sus- tified a universal vitamin D dosage that will consistently suit tained. If the result is <30 ng/mL, continuation of prescription the needs of all patients. Individual medical history, lifestyle, level supplementation is recommended. Once 30 ng/mL is geographic location, body composition, and other factors all reached, daily supplements of a lower dose are continued play a role in determining the proper dose. Furthermore, some along with periodic monitoring of serum levels. Table 2 out- diseases limit the use of vitamin D supplementation, such as lines the generally accepted assessment categories. Currently, sarcoidosis, primary hyperparathyroidism, oat cell lung can- over-the-counter products range from 400 to 2,000 IU; thus, cer, and non-Hodgkin’s lymphoma. These considerations re- it is important to read the product label carefully. inforce the need for a knowledgeable physician and registered Nutrition411.qxd:Layout 1 4/2/09 10:29 AM Page 10 dietitian (RD) to ensure proper treatment and monitoring.3 • Research now shows that activated vitamin D (calcitriol) is made in most tissues and cells, not only the kidneys, New research has found that injury causes skin cells to re- quire additional vitamin D. The genes controlled by vitamin • Vitamin D fortification is required only in liquid milk.
D promote creation of an antimicrobial peptide called cathe- Other dairy products do not provide vitamin D unless licidin, which the immune system uses to fight infections. Skin wounds require vitamin D3 to protect against infection and • Sensible sun exposure for the face, arms, and legs to the begin the normal repair process. A vitamin D deficiency may sun should include approximately 15 to 20 minutes be- compromise the body’s innate immune system, which works fore applying sunscreen at least three times/week. It is to resist infection, making a patient more vulnerable to mi- estimated that a Caucasian could make 10,000 IU vita- crobes. These responses are a previously unrecognized part of the human injury response.10 This innate immunity process • Vitamin D percentage on food labels can be converted also links adequate vitamin D levels to the reduction in in- to IU by using the current AI of 400 IU. For example, if the label states the food provides 25% of the require- Rigorous studies on how the correction of a vitamin D de- ment for vitamin D, the product contains 100 IU/serving ficiency may hasten wound healing still are needed. At this juncture, the evidence is anecdotal. A post on Dr. John Can- • Always make sure you request and review the actual test nell’s vitamin D website11 describes how a pain management results because different labs use different amounts to physician approached care of a 75-year-old female patient who weighed 250 pounds. The physician prescribed 50,000 IUof vitamin D per week for underlying osteoporosis. When he Coming next month — transcultural issues in nutrition saw the patient for a follow-up exam, he discovered she hadtaken the vitamin D supplement daily instead of weekly. The physician then noticed that the patient had remarkable heal- 1. Looker AC, Pfeiffer CM, Lacher DA, Schleicher RL, Picciano MF, Yetley EA. Serum 25-hydroxyvitamin D status of the US population: 1988-1994 ing of venous stasis ulcers in her bilateral lower extremities.
compared with 2000-2004. Am J Clin Nutr. 2008;88(6):1519–1527. These ulcers previously had remained stagnant for more than 2. Wootton A. Improving the measurement of 25-hydroxyvitamin D. Clin 5 years, despite the best efforts of the local wound care clinic.
3. Holick MF. Vitamin D deficiency—review article. N Engl J Med.
Hopefully in the near future, we will see formal studies on this 4. Hatun S, Islam O, Cizmecioglu F, et al. Subclinical vitamin D deficiency topic. Vitamin D just might take a place next to the other nu- is increased in adolescent girls who wear concealing clothing. J Nutr.
trients that are essential for wound healing.
5. Autier P, Gandini S. Vitamin D supplementation and total mortality: a meta-analysis of randomized control ed trials. Arch Intern Med.
Dr. Michael Holick3 observed, “Rickets can be considered 6. Vieth R, Bischoff-Ferrari H, Boucher B, et al. The urgent need to recom- mend an intake of vitamin D that is effective. Am J Clin Nutr.
the tip of the vitamin D deficiency iceberg.” The bulk of the problems are below the surface; this deficiency can affect any- 7. The National Academies. Committee membership information: dietary reference intakes for Vitamin D and calcium. Available at: www.nation- one, including healthcare professionals. One physician reports alacademies.org/cp/committeeview.aspx?key=49031. Accessed March that his father, a widower with diabetes, a fractured hip, and depression, had a 25(OH)D level that was only 6 ng/mL. An- 8. Hathcock JN, Shao A, Vieth R, Heaney R. Risk assessment for vitamin D. Am J Clin Nutr. 2007;85(1):6–18.
other anecdote recounts the story of a morbidly obese woman 9. Heaney RP, Davies KM, Chen TC, Holick MF, Barger-Lux MJ. Human with diabetes in great pain during her stay at a rehabilitation serum 25-hydroxycholecalciferol response to extended oral dosing withcholecalciferol. Am J Clin Nutr. 2003;77(1):204–210.
hospital. When tested, her 25(OH)D level was <4 ng/mL. In 10. Schauber J, Dorschner RA, Coda AB, et al. Injury enhances TLR2 func- this day of advanced medicine, are we forgetting to check for tion and antimicrobial peptide expression through a vitamin D-depen-dent mechanism. J Clin Invest. 2007;117(3):803–811.
basic nutrient deficiencies that may help preserve the quality 11. The Vitamin D Council. The Vitamin D Newsletter, April 2008. Available of life? As more and more light is shined on vitamin D, it is at: www.vitamindcouncil.org/newsletter/2008-april.shtml. Accessed hoped that these types of stories will become the exception, Dr. John Cannell: www.VitaminDcouncil.com Dr. Michael Holick: www.uvadvantage.org and www.vitamindhealth.orgNational Academy of Sciences. Unraveling the Enigma of Vitamin D: • The correct test for evaluating vitamin D (also known www.beyonddiscovery.org/content/view.article.asp?a=414 • It is only necessary to test (1,25[OH]2D), or calcitriol, if the patient has advanced kidney disease, a high calciumlevel, or certain diseases that induce a vitamin D hyper-

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