US Pharm. 2010;35(8):20-27.
Most older adults do not eat a healthy diet each day. Mild vitamin deficiencies are very common among seniors, and particularly so among the frail and institutionalized elderly.1 Anemia, cognitive impairment, an increased propensity for developing infections, and poor wound healing are among the associated manifestations of mild vitamin deficiencies in the elderly.1 While single vitamin deficiencies do occur, usually multiple vitamin deficiencies are seen with general malnutrition.2 Severe vitamin deficiency can lead to irreversible organ damage.1
The causes of vitamin and mineral deficiencies (TABLE 1) are varied. Older adults may not consume certain foods or may consume them in inadequate amounts. Smoking tobacco, malabsorption disorders, gastrointestinal (GI) surgery, Helicobacter pylori infection of the GI tract, alcohol overconsumption, drug adverse effects, and drug-nutrient interactions may also contribute.2,3 Age-related changes may cause seniors to eat less (i.e., satiety with less food) due to the presence of more hormones that decrease appetite and fewer neurotransmitters that stimulate appetite.3In the United States and other developed countries, vitamin deficiencies result primarily from poverty, food fads, drugs (TABLE 2), alcoholism, or extended or inadequately supplemented treatment with parenteral nutrition.4 Among frail and institutionalized elderly people with protein-energy malnutrition, mild vitamin deficiency is a common finding.4 In developing countries, vitamin deficiencies can ensue secondary to lack of access to nutrients.4 It requires weeks to months of undernutrition for deficiencies of water-soluble vitamins (except vitamin B12) to develop, whereas deficiencies of fat-soluble vitamins, and of vitamin B12, require more than a year to develop due to larger body stores.1,4
While undernutrition can be attributed to a sole cause, typically comorbidities act together, contributing to undernutrition.3 Of note, the appearance of people who are undernourished may not change; if there is only a specific nutrient that is lacking (e.g., protein), an individual's weight may be normal or higher.3 Many undernourished seniors, however, are clearly underweight and have little or no body fat.3 Mild vitamin deficiency is commonly seen in the frail and institutionalized elderly population with protein-energy malnutrition.4 Undernutrition in the elderly is often an integral part of a general decline.3 Furthermore, there are disorders that increase energy requirements while at the same time decreasing appetite (TABLE 3).3
Dietary requirements for vitamins and other nutrients may be expressed in several ways4:
1) recommended daily allowance (RDA), which is used to meet the needs of 97% to 98% of healthy people;
2) adequate intake (AI), which is based on observed or experimentally determined estimates of nutrient intake by healthy people and used when data to calculate an RDA are insufficient; and 3) tolerable upper intake level (UL), which is the highest dosage of a nutrient most adults can ingest daily without risk of adverse health effects.4
Dietary Reference Intake tables developed by the Food and Nutrition Board of the Institute of Medicine are available online at http://fnic.nal.usda.gov, in the Dietary Guidance section of the Food and Nutrition Information Center Web site maintained by the U. S. Department of Agriculture. Included in these tables is a Dietary Reference Intake for Older Adults that includes RDAs, AIs, and ULs. The Web site also provides links to information on diet and disease.
Active research and continued controversy surround the topic of vitamin intake sufficient to prevent classic vitamin deficiencies (e.g., scurvy, beriberi), but not necessarily sufficient for optimum health.4 While the benefit of routine vitamin supplementation for healthy seniors is controversial, there is evidence that a multivitamin supplement improves immune status in healthy elderly individuals.1
Supplementation with a multivitamin containing at least the RDAs is recommended for seniors at risk for vitamin deficiency, since tests to diagnose early deficiencies can be difficult and expensive.1 The most valuable means of screening patients for vitamin deficiency (or toxicity) is a thorough nutrition-focused history and physical exam.2
Common Manifestations of Mild Vitamin Deficiencies in the Elderly
Anemia: Anemia is generally recognized as a common clinical problem in elderly individuals.5 According to the World Health Organization (WHO) criteria, anemia is consistent with a hemoglobin concentration of <13 g/dL in men and <12 g/dL in women.5 Data indicate a high prevalence of anemia among hospitalized seniors, patients associated with geriatric clinics, and institutionalized seniors.5 This is in contrast to healthy seniors, in whom the prevalence of anemia is relatively low.5 The most prevalent anemias in elderly populations are those associated with blood loss, inflammation and chronic disease, and protein-energy malnutrition.5
In elderly patients with ineffective erythropoiesis (formation of erythrocytes), it is important for pharmacists to note that microcytosis (low mean corpuscle volume: [MCV]) should suggest sideroblastic anemia, while macrocytosis (high MCV) strongly suggests vitamin B12 or folic acid deficiency.5,6 Pernicious anemia (megaloblastic anemia due to failure of the gastric mucosa to secrete adequate and potent intrinsic factor, resulting in malabsorption of vitamin B12) has been reported with increasing frequency, particularly in seniors.2
Cognitive Impairment: More common causes of vitamin B12 deficiency in the elderly are hypochlorhydria (decreased gastric acid production noted to occur in up to 15% of seniors older than age 65) and Helicobacter pylori infection of the stomach.1 Vitamin B12 deficiency can result in both hematologic signs and symptoms (e.g., anemia) and neurologic signs and symptoms such as nonspecific paresthesias (e.g., numbness) of the extremities and gait ataxia.1 Neuropsychiatric symptoms may occur secondary to vitamin B12 deficiency, such as delirium manifesting as slowed thinking, confusion, memory loss, and depression, which may be difficult to differentiate from Alzheimer's disease.7 Low serum folate levels have been shown to be associated with atrophy of the cerebral cortex, thought to be a possible result of hyperhomocysteinemia.7 It should be noted, however, that although deficiencies of vitamin B12 and folic acid are common in frail seniors with cognitive impairment, supplementation with folic acid and vitamin B12 rarely alters the course of cognitive decline that is slowly progressive.7
Vitamin D Deficiency and Seniors
In the U. S., severe vitamin D deficiency is rare; however, most Americans do not achieve adequate vitamin D levels from sources that include sunlight, diet, and supplements.8-10 Approximately 90% of adults between the ages of 51 and 70 do not get enough vitamin D from their diet.9,10 Data indicate individuals with low vitamin D levels have lower bone density and are at risk for fractures as they age; seniors, in particular, may have lower blood levels of vitamin D compared to younger counterparts, especially those who have minimal exposure to sunlight.11,12 Vitamin D deficiency causes osteomalacia in adults (producing bone pain in some and possibly contributing to osteoporosis) and rickets in children.4,8
Drug-induced osteomalacia is associated with anticonvulsant therapy (e.g., phenytoin, phenobarbital, primidone, carbamazepine), rifampin, and some hypnotic agents.13 Institutionalized patients or individuals receiving multiple concomitant anticonvulsant therapy are usually the only patients in which anticonvulsant-associated osteomalacia is present. Kidney failure and primary biliary cirrhosis are examples of conditions that alter vitamin D metabolism.8
A nutrition-based dietary history complements a nutrition-focused physical examination by assisting in revealing the likelihood of malnutrition and vitamin deficiencies. Drugs can affect vitamin status and ultimately affect a patient's nutritional status. Pharmacists' awareness of these concepts can help in tailoring the medication regimen to maximize therapeutic benefit while reducing the risk of drug-nutrient interactions.
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8. Osteomalacia. MayoClinic.com. http://www.mayoclinic.com/ health/osteomalacia/DS00935. Accessed July 22, 2010.
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10. Moore C, Murphy MM, Keast DR, Holick MF. Vitamin D intake in the United States. J Am Diet Assoc. 2004; 04:9980-9983.
11. Prevention: vitamin D. National Osteoporosis Foundation. http://www.nof.org/prevention/ vitaminD.htm. Accessed July 22, 2010.
12. Vitamin D and related compounds (oral route, parenteral route). MayoClinic.com. Original Article: http://www.mayoclinic. com/health/drug-information/DR602171. Accessed January 16, 2009.
13. O'Connell MB, Seaton TL. Osteoporosis and osteomalacia. In: DiPiro JT, Talbert RL, Yee GC, et al, eds. Pharmacotherapy: A Pathophysiologic Approach. 6th ed. New York, NY: McGraw-Hill; 2005:1645-1669.
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