Vitamin D deficiency linked to higher risk for hypothyroidism
Click Here to Manage Email Alerts
Vitamin D deficiency may increase one’s risk for developing autoimmune hypothyroidism, according to study findings published in BMC Endocrine Disorders.
“Adequate vitamin D levels through sun exposure or dietary supplementations could prevent autoimmune hypothyroidism, where the body’s immune system attacks its own thyroid cells,” Peter McGranaghan, PhD, data analytics consultant at the Miami Cancer Institute of Baptist Health South Florida, told Healio. “Health care initiatives such as mass vitamin D deficiency screening among at-risk populations such as elderly, obese, indoor and sedentary individuals and prompt treatment with dietary supplementations could significantly decrease the risk for hypothyroidism in the long term.”
McGranaghan and colleagues analyzed data from 7,943 adults aged 20 years or older who participated in the National Health and Nutrition Examination Survey from 2007 through 2012 (mean age, 47 years; 51.5% women). Participants were categorized based on serum 25-hydroxyvitamin D levels. Vitamin D deficiency was defined as a level of less than 20 ng/mL, intermediate levels were defined as 20 ng/mL to 30 ng/mL, and optimal vitamin D was defined as 30 ng/mL or more. Participants were considered to have hypothyroidism if they had a thyroid-stimulating hormone level of more than 5.6 mIU/L or were on levothyroxine. Those with a TSH between 0.34 mIU/L and 5.6 mIU/L and not taking any thyroid medication were categorized as normal controls.
Of the study cohort, 7.7% had hypothyroidism. About 80% of participants had health insurance, 58.1% said they engaged in some form of physical activity, 75.8% said they never smoked and 78.1% reported drinking alcohol.
“A surprising finding in our study was that majority of the participants had lower levels of physical activity and consumed alcohol,” McGranaghan said. “This was associated with compromised vitamin D status and thereby could have led to hypothyroidism.”
There was a significant association between vitamin D level and hypothyroidism, with 25.6% of hypothyroid patients being vitamin D deficient compared with 20.6% of normal controls. Those with hypothyroidism had a higher prevalence of obesity (40.5% vs. 33.4%), hypertension (47.1% vs. 29.5%), diabetes (19.7% vs. 10.7%), and dyslipidemia (54.9% vs. 44.7%; P < .001 for all) compared with those who did not have hypothyroidism.
After adjusting for variables, the odds for developing hypothyroidism were increased for people with intermediate vitamin D levels (adjusted OR = 1.7; 95% CI, 1.5-1.8) and deficient vitamin D levels (aOR= 1.6; 95% CI, 1.4-1.9).
“Future research should focus on early screening and prompt correction of vitamin D deficiency in susceptible populations such as elderly, obese, indoor and sedentary individuals,” McGranaghan said.
For more information:
Peter McGranaghan, PhD, can be reached at peter.mcgranaghan@charite.de.
Collapse
Read more about
Click Here to Manage Email Alerts