Don’t Become a Statistic, Maintain Adequate Vitamin D Concentrations in Blood
About 90% of hip fractures occur from a simple fall from standing height or less. The risk of falling increase with age from 1-in-5 women 45-49y to nearly 1-in-2 for those >85y along with 1/3 of men. To help educate consumers and provide guidance to manufacturers of fortified foods and beverages, and dietary supplements, the FDA and EFSA Panel on Dietetic Products, Nutrition and Allergies have approved health claims for vitamin D and calcium.
In a randomized, double-blind, placebo-controlled trial (RCT) involving 230 postmenopausal women <75 years with baseline 25(OH)D concentrations < 50 nmol/L (level set as adequate by the Institute of Medicine), Hansen and colleagues compared 3 treatments: 1) daily white placebo & twice monthly yellow placebo, 2) daily white 800 IU vitamin D (D3) & twice monthly yellow placebo, and 3) daily white placebo & twice monthly yellow 50,000 IU D3. They measured serum 25(OH)D3 concentrations, total fractional calcium absorption (TFCA) using dual calcium isotopes, bone mineral density (BMD), and muscle outcomes in these women with an average age of 61y.
By year-end, serum 25(OH)D3 concentrations had increased to ~68 nmol/L and ~113 nmol/L with 800 and 50,000 IU vitamin D3 supplementations compared to placebo group which fell from 50 to 45 nmol/L. TFCA increased in the high-dose (0.6%) and decreased 4.5% and 1.5% in the low-dose and placebo arms, respectively. There were no treatment differences in falls, fractures, muscle outcomes or BMD. In a commentary, Deborah O’Grady wonders if 1 year is an insufficient period of time to see outcome differences. More importantly, these women did have average adequate serum 25(OH)D3 status at baseline (50 nmol/L).
Andrea Wong, CRN vice president of scientific and regulatory affairs, shared her thoughts, “As the discussion portion of the study and the accompanying Editor’s Note pointed out, perhaps the results would have been different had the study gone beyond one year. Additionally, the study doesn’t answer the question as to whether the results would have been different had the study population maintained optimal levels of vitamin D throughout their lives. We do know from other nutrition studies that it is the long-term use of vitamins that often provide the most benefit.”
Who expects to see an effect of supplementation in individuals maintaining healthy vitamin D status? A single RCT shouldn’t dissuade adults everywhere from consuming recommended amounts of vitamin D and calcium to maintain adequate serum 25(OH)D3 (20 ng/mL, 50 nmol/L) concentrations.
Hansen KE, Johnson E, Chambers KR, Johnston MG, Lemon CC, Vo NGT, Marvdashti S. Treatment of vitamin D insufficiency in postmenopausal women: A randomized controlled trial. 2015 JAMA Intern Med doi: 10.1001/jamainternmed.2015.3874
Cummings SR, Melton LJ. Epidemiology and outcomes of osteoporotic fractures. 2002 Lancet doi: 10.1016/S0140-6736(02)08657-9
O’Grady D. How much vitamin D is enough? 2015 JAMA Intern Med doi:10.1001/jamainternmed.2015.3937
Final Rule: Food Labeling: Health Claims: Calcium and Osteoporosis, and Calcium, Vitamin D, and Osteoporosis. 21 CFR 101.72. September 29, 2008
Scientific opinion on the substantiation of a health claim related to vitamin D and contribution to normal bone and tooth development pursuant to Article 14 of Regulation (EC) No 1924/2006. 2014 EFSA J doi: 10.2903/j.efsa.2014.3579
Scientific opinion on the substantiation of a health related to calcium and vitamin D and bone strength pursuant to Article 14 of Regulation (EC) No 1924/2006 – Scientific opinion of the Panel on Dietetic Products, Nutrition and Allergies. 2008 EFJSA J doi: 10.2903/j.efsa.2008.828
Scientific opinion in relation to the authorization procedure for health claims on calcium and vitamin D and the reduction of risk of osteoporotic fractures by reducing bone loss pursuant to Article 14 of Regulation (EC) No 1924/2006 – Scientific opinion of the Panel on Dietetic Products, Nutrition and Allergies. 2008 EFJSA J doi: 10.2930;j.efsa.2010.1609
Scientific opinion on nutrient requirements and dietary intakes of infants and young children in the European Union. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). 2013 EFSA J doi: 10.2903/j.efsa.2013.3408