Vitamin D Benefits for Bones and Beyond: New Dosage Recommendations and Potential Uses

Transcription

1 Vitamin D Benefits for Bones and Beyond: New Dosage Recommendations and Potential Uses Release Date: 08/28/2011 Expiration Date: 08/28/2013 FACULTY: Nicole van Hoey, PharmD FACULTY AND ACCREDITOR DISCLOSURE STATEMENTS: Nicole van Hoey has no actual or potential conflict of interest in relation to this program. ACCREDITATION STATEMENT: Pharmacy PharmCon Inc is accredited by the Accreditation Council for Pharmacy Education as a provider of continuing pharmacy education. Program No.: H01-P/T Credits: 1 contact hour, 0.1 CEU Nursing Pharmaceutical Education Consultants, Inc. has been approved as a provider of continuing education for nurses by the Maryland Nurses Association which is accredited as an approver of continuing education in nursing by the American Nurses Credentialing Center s Commission on Accreditation. Program No.: N-672 Credits: 1 contact hour, 0.1 CEU

2 TARGET AUDIENCE: This accredited program is targeted nurses, pharmacists, and pharmacy technicians practicing in hospital and community pharmacies. Estimated time to complete this monograph and posttest is 60 minutes. DISCLAIMER: PharmCon, Inc does not view the existence of relationships as an implication of bias or that the value of the material is decreased. The content of the activity was planned to be balanced and objective. Occasionally, authors may express opinions that represent their own viewpoint. Participants have an implied responsibility to use the newly acquired information to enhance patient outcomes and their own professional development. The information presented in this activity is not meant to serve as a guideline for patient or pharmacy management. Conclusions drawn by participants should be derived from objective analysis of scientific data presented from this monograph and other unrelated sources. Program Overview: To provide participants with an understanding of new dosing and uses of Vitamin D supplements for bone health and related fields. OBJECTIVES: After completing this program, nurses and pharmacists will be able to: Identify adequate intake vitamin D dosages for appropriate patient populations by age for bone health Describe symptoms indicative of low and high vitamin D levels Review the potential dosages and beneficial effects of vitamin D supplementation on cancer and heart diseases. After completing this program, pharmacy technicians will be able to: In general terms, describe the potential beneficial effects of vitamin D on bone health, cancer and heart disease.

3 Vitamin D Benefits for Bones and Beyond: New Dosage Recommendations and Potential Uses Case Report A mid-50s woman, D.H., comes to the 5-minute osteoporosis screening clinic conducted by the nurse practitioner pharmacist partnership held at your outpatient pharmacy in Vermont. Screening shows low bone mineral density, and the patient s age itself is an osteoporosis risk, especially because consultation identifies an established perimenopausal state. D.H. currently takes calcium supplements in the form of antacid chews when she thinks of them, up to two per day. D.H. uses sunblock often, both alone and in makeup and lotion products; she works in an office full time; and she takes no other medications. D.H. does take a daily multivitamin but has no known diseases for which she regularly visits a physician. Her only recent complaints are achiness and trouble sleeping. As the consulting pharmacist, you are aware of new osteoporosis treatments and new vitamin D and calcium dosage recommendations. You take extra time to research the patient s needs before returning to your consultation with D.H. What is Vitamin D and Why Is It Important? 1,2 Vitamin D, one of four fat-soluble vitamins required by the body, is a potent steroidal vitamin made within the body from cholesterol through a process triggered by ultraviolet (UV) B rays or sunshine. Vitamin D, whether made in the body or obtained from food, is hydroxylated in the liver to the predominant circulating form, 25-hydroxyvitamin D, or calcidiol. Calcidiol is then converted through rehydroxylation to 1, 25-dihydroxyvitamin D, or calcitriol, in the kidneys and tissues. Calcitriol, with a 15-hour half-life, is the primary active form, but the calcidiol half-life in the blood nears 15 days. Vitamin D is best known for its success at eliminating rickets a bone softening disease in children that was considered difficult to treat in the early 20th century. Vitamin D deficiency is the primary cause of rickets and osteomalacia, a similar bone disease of adulthood. Receptors for vitamin D are found throughout the body, including in the bone, pancreas, intestines, and muscle and nerve systems. Vitamin D aids bone health through its primary action of promoting calcium absorption in the gut as well as by regulating serum calcium and phosphorus levels, but it also binds receptors in the immune, neurologic, and cardiovascular systems to regulate cell cycles and organ functions there. 1-3 Since the 1997 Institute of Medicine recommendation of vitamin D 400 IU daily to prevent rickets and osteomalacia, much about our knowledge of sun exposure has changed. As we have limited our sun exposure and increased use of sunblock, alone and in combination skin products, we have reduced the ability of ultraviolet (UV) rays to formulate vitamin D in our bodies. Approximately 1 billion people worldwide have been identified as vitamin D deficient in the 21 st century, and the number is on the rise, in part because of our limited exposure to UV rays. Early symptoms of deficiency are nonspecific and include insomnia, loss of appetite, diarrhea, vision changes, and a burning sensation in the mouth. As vitamin D deficiency remains untreated, Author Program Title Page 1

4 moderate symptoms of periodontal disease and musculoskeletal pain can develop, although neither of these symptoms point directly and clearly to only vitamin D as their causes. As little as 15 minutes of direct sunlight each day is sufficient to synthesize vitamin D in people with adequate serum levels. However, people who are already deficient, and people at risk of deficiency, may require extra vitamin D supplementation. People with dark skin (eg, people with African-American ethnicity), with limited sun exposure, with high use of sunblock, and who live in latitudes north of San Francisco, CA, or Philadelphia, PA, are all prone to receiving inadequate UV rays to synthesize enough vitamin D. People who are obese are at increased risk as well, possibly because of increased vitamin D absorption by fat cells. Elderly people have multiple risks for deficiency, including a limited variety of fortified dietary products with vitamin D and the potential for group residence (eg, long-term care or assisted living facility) that limits their time outdoors. 1-4 As vitamin D deficiency has become more widespread, higher dosages and daily recommendations have been suggested. However, like other fat-soluble vitamins such as A and K, vitamin D is associated with a U curve of effects: too little or too much can cause problems in the body. High vitamin D levels, even serum levels as low as 50 to 60 ng/ml, initially cause general constitutional symptoms of sleepiness, headache, nausea, vomiting, and constipation. Very high vitamin D levels in the blood start affecting calcium levels and pull calcium into the blood and urine, leading to kidney stones. 2,4 Because vitamin D is not found in large amounts in food and is not generally overproduced by the body, too much vitamin D occurs only from excessive supplementation. 2,5 Appropriate dosing for age and condition, and regular monitoring of serum concentrations in at-risk populations, ensure that vitamin D levels in the body are sufficient for health without causing undue effects. New Vitamin D Dosages and Monitoring Recommendations for 2011 Intake and Serum Levels 1,4,6 The recommended intakes of vitamin D from 1997 were based on the limited knowledge of vitamin D benefits and safety at that time, and 400 IU per day was recommended for most people. To complement the primary vitamin D source via sun exposure, and the secondary sources of fortified foods and egg yolks, multivitamins were formulated to contain the daily recommendation. Indeed, vitamin D2 or D3 provided as a supplement appear more effective than fluctuating food intake at providing vitamin D and compensating for limited UV exposure. Since 1997, healthy vitamin D levels have been associated with extraneous, nonbone benefits that might require supplementation above and beyond the basic 400 IU dosage, and some adult multivitamins now contain 800 IU. Dosage differentiation on the basis of risk, disease states, age, sex, and baseline vitamin D levels should also be distinguished as the vitamin s benefits are explored more. Normal serum levels of circulating vitamin D range from 30 to 74 ng/ml, whereas 35 to 40 ng/ml is suggested as a general preventive health goal The new 2010 Institute of Medicine vitamin D dosage recommendations are made to ensure a serum level of 20 ng/ml as a baseline Author Program Title Page 2

5 level of adequacy in most people. In addition to this baseline, the Institute of Medicine has identified three levels of deficiency risks for monitoring: the highest deficiency likelihood, at less than 30 ng/ml; a moderate possibility of deficiency, at 30 to 50 ng/ml; and a mild possibility of deficiency at greater than 50 ng/ml. 2,4,6 To achieve these serum levels, structured recommended dietary intakes (RDIs) of vitamin D and calcium by age, sex, and population have been proposed. These RDIs, as with other US Department of Agriculture suggestions, are divided into estimated average requirements, adequate intake (previously known as the recommended dietary allowance, which reflect the basic needs for most people), and upper levels (indicative of toxicity risk). Men and women ages 19 to 70 years should receive 600 IU daily to meet the adequate intake, with an estimated minimum requirement of 400 IU daily and an upper limit of 4,000 IU daily. Elderly men and women (ie, age older than 70 years) in general should receive 800 IU daily for adequacy, with the same minimum and maximum amounts. Because vitamin D in the body is so closely connected with calcium levels and effects, the Institute of Medicine outlined concomitant calcium requirements according to approximately the same population divisions. For adequate intake, all men and women ages 19 to 50 years, and men age 51 to 70 years, should receive 1,000 mg of calcium each day; women age 51 years or older and men older than 70 years should receive slightly more 1,200 mg daily. The bottom line for health professionals who monitor or recommend vitamin D supplementation is that too much may be as dangerous as too little, so calcium and vitamin D intake should stay within the Institute of Medicine recommendations until more research is available. Vitamin D in Special Needs Populations 4-8 Populations with special needs are not yet entirely delineated in the 2010 vitamin D recommendations. For example, vitamin D requirements for pregnant women are still unclear and may in fact be higher than in the general population. Current guidelines recommend an average requirement of 600 IU daily. As early as 2004, reviews of clinical trials identified the safety of therapeutic vitamin D levels during pregnancy and disputed prior associations with birth defects, including valvular heart disorders. Research in the 21 st century has consistently supported the benefits of even higher vitamin D levels in pregnant or nursing women. In particular, vitamin D serum levels approaching 50 ng/ml in pregnant women have been linked to beneficial bone development in the fetus at as early as 19 weeks of gestation; conversely, poor bone and cardiac development has been identified in fetuses of pregnant women with deficient levels of vitamin D less than 25 ng/ml. As awareness of the importance of vitamin D to multiorgan development increases, additional observational studies in women might identify specific vitamin D dosages or serum level goals for mother and infant health. 7,8 Elderly, particularly those in long-term care or at risk of falls and fractures as a result of arthritis, dementia, or stroke, could require greater intake of vitamin D as well. Working from the basic adequate intake of 600 or 800 IU daily according to age, at-risk elderly with identified deficiency should have blood levels monitored to adjust vitamin D dosages upward toward a normal serum level goal. 9 Approximately 100 IU per day of extra supplementation can increase blood levels 1 ng/ml proportionally within 2 to 3 months of continued use in patients of any age. 1,3 Author Program Title Page 3

6 Finally, young children with anemia might require greater levels of vitamin D to properly control anemia and maintain hemoglobin levels in the body. In 2011, researchers discovered a proportional decrease in anemia risk with each 1-ng/mL increase of vitamin D levels in children. Because low vitamin D levels are related to low hemoglobin levels, vitamin D is a reliable indicator of anemia. However, as with many associations between vitamin D and health, a causal relationship between anemia or hemoglobin and vitamin D has not been determined. 10 Vitamin D use in special and general populations is certainly increasing, and health professionals are responsible for maintaining the safety of people who use over-the-counter or prescription vitamin D products. Pharmacists can monitor serum levels and suggest dosages in tertiary care or physician-contract settings, but the most frequent opportunity for intervention is with the public users themselves, by guiding patients to safe supplements and counseling them on appropriate use. Dosing Considerations 1,3 Vitamin D2, or ergocalciferol, is synthesized in laboratories for prescription capsules of 50,000 IU, but vitamin D3, or cholecalciferol, is the type of vitamin D formulation contained in most over-the-counter tablets and capsules. Vitamin D3 is the preferred formulation because of its similarity to the body s own form and because of its greater efficacy. Although 3,000 to 4,000 IU and even up to 10,000 IU daily can be prescribed to treat severe deficiency, the maximum suggested amount to use over the counter without physician oversight is 2,000 IU daily. Maintenance dosages can range from 800 to 1,000 IU per day. Because vitamin D is fat soluble, it is best absorbed with a fatty meal or snack. A number of medications change vitamin D blood levels and should be given separately. Fat-blocking drugs for weight loss, such as orlistat or cholestyramine, reduce vitamin D absorption from the gut, and antiseizure medications such as phenobarbital or phenytoin affect liver enzymes to increase the hepatic metabolism of vitamin D to an inactive state. Corticosteroids lower vitamin D levels as well by decreasing calcium absorption to cause increased vitamin D metabolism. Pharmacists can use everyday opportunities in their practice settings to guide patients to appropriate vitamin D formulations and dosages for their needs and concomitant medications. As knowledge of diseases associated with vitamin D expands, so too can the pharmacist s counseling role. Vitamin D Disease State and Treatment Claims 2 In part because of its steroid hormone properties, vitamin D has more widespread effects than just calcium regulation. Vitamin D possesses anti-inflammatory and possibly immune-boosting properties that could benefit myriad disease states. Connections proposed between vitamin D levels and autoimmune disorders such as type 1 diabetes mellitus, multiple sclerosis (MS), rheumatoid arthritis, and autoimmune thyroid disease are currently being explored. In an early study of adults with type 1 diabetes, supplementation with 700 IU vitamin D appeared to cause less fluctuation of glucose levels and, thus, better disease control. 3 In a second study, children supplemented with vitamin D from birth had lower risk of type 1 diabetes development as well. 3,8 Observational studies of vitamin D use have identified possible beneficial associations with MS. High vitamin D levels and risk of developing MS may be inversely related, although Author Program Title Page 4

7 no causal relationship has been established yet. Deficient vitamin D levels, and a lack of sunlight exposure, have been distinctly associated with an increased risk of multiple sclerosis, though, and the immune-boosting effects of vitamin D might lessen multiple sclerosis symptoms by protecting nerve cells from immune attack. Although many associations between multiple sclerosis and vitamin D have been made, therapeutic or protective dosages have not yet been determined. 11 Even the confirmed ability of vitamin D to prevent bone breaks might be more complex than simple calcium absorption effects. Muscle fibers that twitch rapidly in response to falls react more appropriately when there are high levels of vitamin D circulating in the body. Although 400 IU vitamin D daily appears to have no effect, 700 IU daily or more can prevent falls and the resultant bone fractures; according to the US Department of Agriculture, benefits of prevention are proportional with increasing dosages of vitamin D. 1,3,12 Other than bone health, perhaps the two most convincing benefits of vitamin D for chronic or complicated diseases are with cardiovascular disorders and cancers. A strong indicator of the link between vitamin D and heart disease is the observational information obtained from the decadesspanning Framingham Heart Study that registers cardiovascular health and disease data on multiple generations of thousands of patients. Participants whose vitamin D levels were deficient specifically, less than 15 ng/ml had at least 60% greater risk of hypertension, heart disease, and heart attacks, indirectly. Meta-analyses of observational and randomized studies have continued to support these results as well, although the cause for cardiac benefits of vitamin D remains unknown. Benefits likely result from multiple mechanisms, including direct changes to blood vessels and the role of vitamin D as a regulator of the renin-angiotensin system and of glycemic control The reasons for reduction of cancer risk by vitamin D are several-fold as well. The general ability of vitamin D to modulate proteins important to cell changes is an obvious starting point for potential research into effects. Changes in the body caused by vitamin D that could protect against cancer development include improved cell differentiation, decreased cell proliferation, and prevention of new blood vessel growth all of which are cell development stages that are involved in cancer formation if regulated poorly by the body. 2 Low vitamin D levels seem to be proportional to cancer occurrences, particularly for colorectal or breast types. Reduced colorectal cancer risk as been observed at 1,000 IU daily of vitamin D, and lower rates of breast cancer were noted in the 15-year Women s Health Initiative Study in people taking at least 400 IU daily of vitamin D. However, the role of vitamin D in pancreatic cancer is less clear, with early studies identifying an adverse relationship between dose and risk instead. More study on pancreatic cancer is needed for clarity; controlled evaluations of vitamin D on all cancer occurrences will be useful to identify a possible causative role, and not just an indicative association, and to identify the true effects of vitamin D on cancer at a cellular level. 17 Case Conclusion Knowledge about the wide-ranging benefits of vitamin D and our body s multiple requirements for this vitamin as part of healthy nutrition continue to expand. If supplementation beyond adequate intake levels does in fact provide distinct benefits for prevention of chronic diseases Author Program Title Page 5

8 and cancers, over-the-counter sales and use in otherwise healthy children and adults will increase as well, providing a role for clinical and community pharmacists to determine, recommend, and advise patients on tolerable yet effective dosages and products. At your consultation with D.H., you identify her low bone mineral density and outline the risks, symptoms, and long-term detrimental effects of uncontrolled osteoporosis. You also emphasize easy osteoporosis prevention and control methods of simple exercises and calcium plus vitamin D intake in dietary and over-the-counter use. You recommend a follow-up with a family physician to identify possible osteoporosis diagnosis and treatment or to actively monitor her bone mineral density levels for prevention. Regarding calcium and vitamin D, you make the following suggestions: Two chewable calcium tablets on occasion are not sufficient to meet the needs of a woman older than 51 years of age. Instead, D.H. can try calcium citrate for good absorption or another calcium tablet of her choice. A minimum of 1,200 mg/d of calcium is adequate. Any calcium supplement should be taken separately from the multivitamin or other sources of calcium, particularly dairy products, for maximum absorption. The two new symptoms that D.H. is experiencing insomnia and ache are nonspecific but suggestive of low vitamin D levels. D.H. is at higher-than-normal risk of vitamin D deficiency because of her aggressive sun block through skin products and sun avoidance and because of her northern latitude residence. On the basis of her age, D.H. should receive at least 600 IU vitamin D daily through her multivitamin, and her multivitamin does meet this adequate intake requirement. If increasing her sun exposure to 15 minutes daily does not improve her symptoms, deficiency may become pronounced, with serum levels less than 30 ng/ml, and may require extra supplementation to correct. You recommend repeat consultation with you and/or the family physician within 2 weeks after increased sun exposure and suggest vitamin D serum level measurement by the physician if symptoms persist. Author Program Title Page 6

9 Works Cited 1. Vitamin D Supplementation in Long-Term Care Residents: A Review of Clinical Effects and Guidelines. Canadian Agency for Drugs and Technologies in Health, 16 Aug Web. 20 Jun Dietary Supplement Fact Sheet: Vitamin D. NIH.gov. National Institutes of Health Office of Dietary Supplements, n.d. Web. 20 Jun Gonzales, Christine. Vitamin D Supplementation: An Update. US Pharmacist (2010): Print. 4. A. Catharine Ross, Christine L. Taylor, Ann L. Yaktine, and Heather B. Del Valle, eds. "Report Brief: Dietary Reference Intakes for Calcium and Vitamin D." iom.edu. National Academies Press, 30 Nov Web. 20 Jun Hollis, Bruce W. and Wagner, Carol L. Assessment of Dietary Vitamin D Requirements During Pregnancy and Lactation. American Journal of Clinical Nutrition (2004): Print. 6. A. Catharine Ross, Christine L. Taylor, Ann L. Yaktine, and Heather B. Del Valle, eds. PDF Summary: Dietary Reference Intakes for Calcium and Vitamin D. iom.edu. National Academies Press, 30 Nov Web. 20 Jun Nassar, Natasha, et.al. Systematic Review of First Trimester Vitamin D Normative Levels and Outcomes of Pregnancy. American Journal of Obstetrics and Gynecology. 7 Apr. 2011: n. pag. Web. 20 Jun Lewis, Sharon, et.al. Vitamin D Deficiency and Pregnancy: From Preconception to Birth. Molecular Nutrition and Food Research: Special Issue The Vitamin D Revolution (2010): Print. 9. Lister T. "Should Long-Term Care Residents Be Supplemented With Vitamin D?" Canadian Journal of Dietetic Practice and Research (2008): Print. 10. "Low Vitamin D in Kids May Play a Role in Anemia." Hopkinschildrens.org. Children's Hospital at Johns Hopkins, 2 May Web. 20 Jun Pierrot-Deseilligny Charles and Souberbielle Jean-Claude. Is Hypovitaminosis D an Environmental Risk Factors for Multiple Sclerosis? Brain. 133.Pt 7 (2010): Print. 12. Warriner, Amy H., et al. "Management of Osteoporosis Among Home Health and Long- Term Care Patients With a Prior Fracture." South Med J (2009): Print. Author Program Title Page 7

10 13. Hsia Judith, et.al. Calcium/Vitamin D Supplementation and Cardiovascular Events. Circulation (2007): Print. 14. Intermountain Medical Center. "Treating Vitamin D Deficiency Significantly Reduces Heart Disease Risk, Studies Find." ScienceDaily, 17 Mar Web. 20 Jun Wang Lu, et.al. Systematic Review: Vitamin D and Calcium Supplementation in Prevention of Cardiovascular Events. Annals of Internal Medicine (2010): Print. 16. Wang, Thomas J., et al. "Vitamin D Deficiency and Risk of Cardiovascular Disease. Circulation. 7 Jan Web. 20 Jun "Vitamin D and Cancer Prevention: Strengths and Limits of the Evidence." cancer.gov. National Cancer Institute Fact Sheet. National Cancer Institute, n.d. Web. 20 Jun Author Program Title Page 8