Presentation on theme: "Vitamin D Deficiency: To D Or Not To D, That Is The Question. Rick Padilla, MD Denver Health March 10, 2009."— Presentation transcript:
Vitamin D Deficiency: To D Or Not To D, That Is The Question. Rick Padilla, MD Denver Health March 10, 2009
Case Mrs. G. is a 68 yo HF with hx of metabolic syndrome and seizure disorder who comes in for routine follow up. She has no acute complaints. Her last seizure was 3 months ago and she has 3-4 seizures per year. Her rx are glucovance 5/500 mg daily, crestor 5 mg qhs, zestoretic 20/25 mg daily, aspirin 81 mg daily, OTC calcium 2 tabs per day and dilantin 300 mg qhs. BP 124/74, P 72, RR 16, BMI 30.2 Physical exam is normal.
Case continued Pertinent studies, HgBA1C = 6.9, LDL = 88, creat cl = 60, spot UA = moderate microalbumin. No recent dilantin level. A Dexa scan done 1 year ago reveals normal BMD with a T score of –0.8. Should you order a 25 OH vitamin D level on this patient?
DH Lab Reference Range INTERPRETIVE guidelines for Vitamin D (25- hydroxy): > 80 ng/mL: Potential toxicity 30-80 ng/mL: Optimum level 20-29 ng/mL: Insufficiency < 20 ng/mL: Deficiency
Vitamin D Basics Units: ng/mL vs. nmol/L 2.5 nmol/L = 1 ng/mL If data are in nmol/L, divide by 2.5 for ng/mL Rule of thumb For every 100 IU vitamin D3 ingested, blood level of 25-OH-D increases by 1 ng/mL 1 g of D3 or D2 = 40 IU
Prevalence of Vitamin D Deficiency In several studies, 40 to 100% of U.S. and European elderly men and women still living in the community are vitamin D deficient More than 50% of postmenopausal women taking rx for osteoporosis are vitamin D deficient (Holick et al. J Clin Endocrinol Metab 2005) 45/80 (56.2%) of geriatric patients in a UCDSOM study of vit. D education intervention study were vitamin D deficient. (VandeGriend et al. J Am Pharm Assoc 2008)
Vitamin D Levels in the LUCHAR Dataset 34/139 (24.5%) normal 40/139 (28.8%) insufficiency 65/139 (46.8%) deficiency Mean 22.5 ng/mL Range < 5 – 52 ng/mL
Yetley EA. Am J Clin Nutr 2008;88(suppl):558S-64S. nmol/L 25-OH-D levels (nmol/L) decrease with age, % body fat and BMI
D3 ≠ D2 ≠ 1 ,25-di(OH)-D3 D3 is made in the skin* (or ingested in supplements) – not biologically active Cholecalciferol D2 is from plants** (not humans) – only 1/3 as active as D3 Ergocalciferol 1 ,25-di(OH)-D3 is converted in the kidney and other tissues - biologically active “Vitamin D” Calcitriol 25-OH-D is the storage form, NOT biol. active *From 7-dehydrocholesterol**From ergosterol
Sources of Vitamin D Exposure to sunlight Dietary Sources Dietary Supplements
Exposure to Sunlight 5-10 minutes of direct exposure to the arms and legs = 3000 IU of vitamin D3 In a study of 69 healthy subjects age 18-29 in Boston, 36% had 25 OH vit D level < 20 ng/ml at the end of winter. The prevalence decreased to 4% by the end of summer. (Tangpricha Am J Med 2002) Multiple studies show vitamin D def. common in sunny areas when most of the skin is shielded from the sun (Saudi Arabia, United Arab Emirates, Turkey, India and Lebanon)
Holick M. NEJM 357;3:266-280. Sources of Vitamin D
Holick M. NEJM 357;3:266-280 Synthesis and Metabolism of Vitamin D in the Regulation of Calcium, Phosphorus, and Bone Metabolism
1,25 OH Vitamin D Effects Increased calcium absorption in the gut Increased PTH mediated bone resorption Decreased renal calcium and phosphorus excretion Decreased PTH secretion Increased bone calcification
PTH Effects Increases tubular reabsorption of calcium and stimulates the kidney to produce 1,25 OH vitamin D Activates osteoblasts, which then stimulates the activation of osteoclasts, which dissolve mineralized collagen matrix in the bone, causing osteopenia and osteoporosis and increasing the risk of fracture. Causes phosphaturia. A low Ca-Phos product leads to decreased mineralization of the collagen matrix= rickets in kids and osteomalacia in adults
Osteomalacia Softening of the bone due to impaired mineralization due to low Ca-Phos product. Symptoms include isolated or generalized bone pain, muscular weakness, and weight loss 93% of 150 persons 10 to 65 year old seen in an ED in Minnesota with muscle aches and bone pain were deficient (< 20 ng/ml) in vitamin D and 28% had severe deficiency (< 8 ng/ml) (Plotnikoff, Mayo Clin Proc 2003)
Non-classical Actions of Vitamin D Suppress cell growth/proliferation Regulate apoptosis Modulate immune responses Susceptibility to infections Susceptibility to autoimmune disorders – MS, T1DM Effects in transplantation immunity Modulate keratinocyte differentiation and function Key role in psoriasis therapy Suppress renin-angiotensin system Stimulate insulin secretion Control neuromuscular function and the brain Dusso AS, et al. Am J Physiol–Renal Physiol 2005;289:F8-F28.
Mechanisms of Vitamin D Deficiency Reduced skin synthesis - Sunscreen use (SPF 15 reduces vitamin D3 synthesis by 99%) - Skin pigmentation - Aging (reduction of 7 dehydrocholesterol reduces vitamin D3 synthesis by 75% in a 70 year old) - Season, latitude and time of day -Patients with skin grafts for burns
Mechanisms of Vitamin D Deficiency Continued Impaired availability of vitamin D due to inadequate dietary intake, malabsorptive disorders and obesity (sequestration of vitamin D in body fat) Impaired hydroxylation by the liver due to liver disease Increased hepatic catabolism due to medications Impaired renal production of 1,25 –OH vit. D in stage 4 and 5 CKD Renal loss of vit. D and vit. D binding proteins in nephrotic syndrome
Medications That Increase Catabolism of Vitamin D via P450 Enzyme Activity Phenytoin Phenobarbital Carbamazepine Isoniazid Theophylline Rifampin Glucocorticoids HAART
Vitamin D and Fracture Risk Among 3270 elderly French women given 1200 mg calcium and 800 IU of vit D3 daily for 3 years, the risk of hip fracture and nonvertebral fracture decreased by 43% and 32% respectively (Chapuy, NEJM 1992) In 389 subjects over 65 years old, 700 IU of vit D3 and 500 mg per day of calcium decreased nonvertebral fracture by 58% compared to placebo. (Dawson-Hughes, NEJM 1997)
Dawson-Hughes B et al. N Engl J Med 1997;337:670-676 Number of First Nonvertebral Fractures among All Subjects, According to Skeletal Site
Vitamin D and Fracture Risk A meta-analysis of 7 RCT’s evaluating fracture risk in pts given 400 IU of vit D3 per day revealed little benefit. In studies using 700-800 IU of of vitamin D3 per day, the RR of hip fracture and nonvertebral fracture were reduced by 26% and 23% respectively compared to calcium and placebo. (Bischoff- Ferrari, Am J Clin Nutr 2006)
Vitamin D and Falls Vitamin D deficiency causes muscle weakness because skeletal muscle has a vitamin D receptor and may require vitamin D for maximal function. A meta-analysis of 5 RCT with a total of 1237 subjects revealed that increased vitamin D intake reduced the risk of falls by 22%. On further evaluation, 400 IU of vitamin D per day was not as effective 800 IU vitamin D per day in reducing the risk of falls. (Bischoff- Ferrari, Am J Clin Nutr 2006) In an RCT done in a NH, residents receiving 800 IU of vitamin D2 per day plus calcium had a 72%reduction in the risk of falls compared with placebo. (Broe, J Am Geriatr Soc, 2007)
Evidence for Role of Vitamin D in CVD Framingham Offspring Study 1739 subjects (mean 59 yr, 55% F, all C) No prior CVD Mean 25-OH-D 19.7 ng/mL 28% with 25-OH-D <15 ng/mL 9% with 25-OH-D <10 ng/mL 5.4 yr follow-up 120 developed first CV event Wang TJ, et al. Circulation 2008;117:503-511.
Evidence for Role of Vitamin D in CVD: Framingham Offspring Adj. for age, sex Adj for *covar. Adj. for *covar., CRP 25-OH-D >151.00 10 to <152.07 (1.19-3.61) 1.93 (1.09-3.42) 2.07 (1.16-3.69) <103.19 (1.70-5.99) 2.51 (1.30-4.82) 2.43 (1.23-4.80) 25-OH-D >151.00 10 to <151.45 (0.74-2.82) 1.06 (0.53-2.13) 1.05 (0.52-2.13) <101.66 (0.64-4.28) 1.00 (0.35-2.85) 1.08 (0.37-3.16) Hypertension No HTN Wang TJ, et al. Circulation 2008;117:503-511. Hazard ratios ng/mL *Covar. SBP, anti-HTN, DM, cig, total-HDL, BMI, creat
Evidence for Role of Vitamin D in CVD Health Professionals Follow-up Study Prospective trial nested case control 18,225 M age 40-75 (mean 63.8 yr) 94% C No known CVD, baseline 25-OH-D 24.5 vs. 23 ng/mL 10 yr follow-up 454 with nonfatal MI or fatal CHD Giovannucci E, et al. Arch Intern Med 2008;168(11):1174-1180. Compared with 25-OH-D >30 ng/mL <15 ng/mL 15-22.5 ng/mL 22.6-29.9 ng/mL RR of MI after adjustment* 2.09 (1.24-3.54) 1.43 (0.96-2.13) 1.60 (1.10-2.32) *FHx MI, BMI, EtOH, activity, DM, HTN, ethnicity, region, marine -3 intake, LDL, HDL, TG
Vitamin D and Hypertension 148 F age 75 yr with 25-OH-D level <50 nmol/L received calcium 600 mg plus 400 IU D 3 BID vs. calcium 600 mg alone BID over 8 weeks Pfeifer M, et al. J Clin Endocrinol Metab 2001;86:1633-37. InitialFinal Ca onlyVit. D + CaCa onlyVit. D + Ca 25-OH-D (nmol/L) 24.625.744.4 (17.8 ng/mL) 64.8 (25.9 ng/mL) PTH (pmol/L) 6.1 5.34.6 SBP (mmHg) 140.6144.1134.9131.0 DBP (mmHg) 82.684.775.777.5 HR (mmHg) 74.175.473.971.3
Vitamin D and Hypertension In a study of hypertensive patients who were exposed to ultraviolet B radiation three times per week for 3 months, 25 OH vitamin D levels increased by approximately 180% and both SBP and DBP were reduced by 6 mm Hg. (Krause, Lancet 1998) Proposed mechanism: The 1,25 OH vitamin D produced in the kidney enters the circulation and down regulates renin production in the kidney
Studies Needed of Interactions Between Vitamin D and CVD Prospective studies to prove that vitamin D deficiency results in increased CVD events Well-designed studies to determine mechanisms for increased risk Prospective studies to prove that adequate vitamin D replacement decreases CVD events Studies to determine optimal formulation, dosing, target levels
Vitamin D and Diabetes In 10,366 children in Finland given 2000 IU of vitamin D3 per day during their first year of life and then followed for 31 years, the risk of type 1 DM was reduced by 80%. In subset analysis, among children with vitamin D deficiency, the risk was increased by 200%. (Hyponen, Lancet 2001) Combined daily intake of 1200 mg of calcium and 800 IU of vitamin D lowered the risk of type 2 diabetes by 33 % compared to daily intake of less than 600 mg calcium and less than 400 IU of vitamin D. (Pittas, Diabetes Care 2006) Proposed mechanism: The 1,25 OH vitamin D produced in the kidney enters the circulation and stimulates insulin secretion in the islet cells of the pancreas
Vitamin D and Cancer Both prospective and retrospective epidemiologic studies reveal that levels of 25 OH vitamin D below 20 ng/ml are associated with a 30-50% increased risk of incident colon, prostate and breast cancer, along with higher mortality from these cancers The probable mechanism is that colon, prostate and breast express 25-OH vitamin D 1-alpha hydroxylase and produce 1,25 OH vitamin D locally to control genes that help prevent cancer by limiting cellular proliferation and differentiation by inhibiting angiogenesis and inducing apoptosis
Vitamin D Deficiency and All Cause Mortality Retrospective analysis of 13,331 adults 20 years or older from NHANES III testing association of low 25 OH vitamin D and all cause, cancer and cardiovascular mortality Median follow up was 8.7 years, during which there were 1806 deaths, including 777 from CVD In multivariate models (adjusted for baseline demographics and traditional and novel CVD risk factors), compared with the highest quartile, being in the lowest quartile (25 OH vitamin D <17.8 ng/ml) was associated with a 26% increased rate of all cause mortality, (95% CI, 1.08-1.46. Cancer and CVD mortality was not statistically significant. Conclusion: Lowest quartile of 25 OH vitamin D (<17.8 ng/ml) is independently associated with all cause mortality in the general population. (Melamed, Arch Intern Med, 2008)
Copyright restrictions may apply. Melamed, M. L. et al. Arch Intern Med 2008;168:1629-1637. Restricted cubic spline showing the fully adjusted associations between serum 25- hydroxyvitamin D (25[OH]D) levels and all-cause mortality in 13 331 participants of the Third National Health and Nutrition Examination Survey
Ginde et al, Arch Intern Med 2009 Association Between 25- OH Vitamin D and URI Retrospective analysis of 18,883 subjects 12 and older from NHANES III The median serum 25 OH vit D was 29 ng/mL. Recent URI was reported by 24% with 25 OH vit D 30 ng/mL (p<0.001). The association between 25 OH vit D and URI higher in those with asthma (OR 5.67) and COPD (OR 2.26) Conclusion: Serum 25 OH vit D levels are inversely associated with recent URI.
Copyright restrictions may apply. Ginde, A. A. et al. Arch Intern Med 2009;169:384-390. Participants with recent upper respiratory tract infection (URTI) stratified by serum 25- hydroxyvitamin D level (to convert to nanomoles per liter, multiply by 2.496) and season
Vitamin D Deficiency and Other Conditions Linked to increased incidence of : Schizophrenia Depression Reactive Airway Disease
Who Should Be Screened for Vitamin D Deficiency Elderly Home bound or institutionalized patients Patients with known or suspected malabsorption Patients with osteoporosis or osteopenia CKD patients Chronic liver disease patients Patients with nonspecific musculoskeletal pain Patients on medications that induce P-450 enzyme activity Obese
Treatment of Vitamin D Deficiency 50, 000 IU capsule of vitamin D2 (erogocalciferol) once per week for eight weeks, repeat for another 8 weeks if 25 OH vitamin D is < 30 ng/ml 50, 000 IU capsule of vitamin D2 (erogocalciferol) once per week for eight weeks, then 50,000 IU of vitamin D2 every 2 to 4 weeks thereafter for maintenance. If malabsorption syndrome, 50,000 IU of vitamin D2 every day or qod + the use of a tanning bed for 30- 50% of the time recommended for tanning until deficiency corrected, then maintenance therapy If stage 4 or 5 CKD, 0.25-1.0 ug of 1,25 dihydroxyvitamin D3 (calcitriol) bid
Preventive and Maintenance Measures to Avoid Vitamin D Deficiency Sensible sun exposure- 5-30 minutes of exposure of arms and legs between 10 am and 3 pm twice a week is often adequate. 50,000 IU of vitamin D2 every 1-4 weeks 1000 IU of vitamin D3 per day 100,000 IU of vitamin D3 once every 3 months maintains 25 OH vitamin D levels at > 20 ng/ml and is also effective at reducing fracture risk
Holick M. N Engl J Med 2007;357:266-281 Strategies to Prevent and Treat Vitamin D Deficiency
Vitamin D Intoxication Common symptoms:anorexia, nausea and vomiting, polyuria, polydipsia, weakness and pruritus Lab abnormalities: AKI, hypercalcemia and hyperphosphatemia Treatment: stop vitamin D, low calcium diet, acidify the urine and steroids
Mrs. G. Should you order a 25 OH vitamin D level on this patient?
Mrs. G. Age 68 BMI 30.2 DEXA with normal BMD (T score –0.8) On OTC calcium On dilantin
Mrs. G. 25 OH vitamin D level = 18 ng/ml Was started on ergocalciferol 50,000 IU per week x 8 weeks Repeat 25 OH vitamin D level after treatment = 35 ng/ml Now on maintenance therapy of ergocalciferol 50,000 IU every 4 weeks
Take Home Points Vitamin D deficiency is common 25 OH vitamin D is a predictor of bone health in terms of fracture risk and risk of falls 25 OH vitamin D is also potentially an independent predictor of risk of cardiovascular disease, hypertension, cancer, diabetes, all cause mortality, and URI At least 800 IU of vitamin D3 per day is needed to maintain vitamin D sufficiency Sensible sun exposure is a great way to maintain vitamin D sufficiency