Related Experiment Video
Updated: Nov 4, 2025
A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
Supplemental Vitamin D Increased Serum Total 25-Hydroxyvitamin D in the US Adult Population During 2007-2014
Rosemary L Schleicher1, Maya R Sternberg1, Nancy Potischman2
1National Center for Environmental Health, CDC, Atlanta, GA, USA.
Background:
Data from the 2007-2010 NHANES suggested that vitamin D supplements contributed to increased serum concentrations of 25-hydroxyvitamin D [25(OH)D] in the US population.
Objectives:
We sought to determine whether 25(OH)D continued to increase during NHANES 2011-2014 and whether associations of 25(OH)D with preselected covariates differed across time periods.
Methods:
For this study, 25(OH)D was measured in adults (≥20 y) using LC-MS/MS. Descriptive and regression analyses were stratified by survey period to investigate the effects of age, race-Hispanic origin, sex, season, BMI, dietary vitamin D, and vitamin D-containing supplements. A multiple linear regression model was used to assess 25(OH)D changes between two 4-y survey periods, namely 2007-2010 and 2011-2014.
Results:
We observed several significant concomitant increases between 2007-2010 and 2011-2014: unadjusted mean 25(OH)D increased by 2.7 nmol/L (95% CI: 0, 5.4 nmol/L; P = 0.048), the percentage of persons taking any vitamin D-containing supplements increased 2.9% (95% CI: 0.03, 5.5%; P = 0.0314), and the percentage of persons taking high-dose (≥1000 IU/d) vitamin D-containing supplements increased 8.6% (95% CI: 6.9, 9.9%; P < 0.0001). With covariate adjustment, the increase in 25(OH)D from 2007-2010 to 2011-2014 was no longer statistically significant [1.4 nmol/L (95% CI: -3.0, 0.23 nmol/L; P = 0.09)]. After adjustments, several large differences in 25(OH)D remained, namely non-Hispanic blacks had 25(OH)D 22 nmol/L lower than that of non-Hispanic whites, and users of vitamin D-containing supplements ≥1000 IU/d had 25(OH)D 31 nmol/L higher than that of nonusers.
Conclusions:
After adjusting for vitamin D supplement dose, the overall adjusted increase in 25(OH)D was no longer statistically significant, suggesting that changes in US adults' 25(OH)D concentrations between NHANES periods 2007-2010 and 2011-2014 may primarily be associated with changes in vitamin D supplementation.
Related Concept Videos
01:23Role of Skin in Vitamin D Synthesis
The solar UV B rays (290-315 nm) are absorbed by the skin, and 7-dehydrocholesterol (provitamin D3) photolyzes it to previtamin D3, which undergoes a rapid transformation to vitamin...
01:25Role of Vitamins in Maintaining Bone Health
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...
01:21Skeleton and Calcium Homeostasis
01:22Connective Tissue Cell Types
Fat cells (adipocytes), smooth muscle cells (myoblasts), and bone cells (osteoblasts) are some connective tissue cell types. Some immune system cells...
01:17Hormones and Bone Tissue
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
01:30Vitamins