Too Little of the Sunshine Vitamin – A Factor in Metabolic Syndrome
Metabolic syndrome, a combination of high blood pressure, increasing blood sugar levels, and being overweight has become more prevalent in the United States over the past 20 years or so. The reasons for this include eating too much highly processed, refined snack foods and too little exercise. Unfortunately, everywhere else in the world that the standard American diet has made inroads has also seen an increase in metabolic syndrome. China is no exception.
Interestingly, Chinese researchers found that adolescents and young adults already at risk of developing metabolic syndrome were also low in vitamin D levels. Vitamin D is synthesized in the body following exposure to sunlight, and those who stay indoors often or live in colder climates are especially at risk. In fact, the researchers found that the young men and women with the lowest levels of circulating vitamin D were 2.5 times at risk than those with lighter deficiencies. But overall, 78 percent of the individuals tested were low in vitamin D.
Whether or not low vitamin D is a cause or result of metabolic syndrome remains to be seen. Fortunately, low levels are easily overcome through daily supplementation. There are many ways of getting the vitamin D3 (the form your body ultimately synthesizes) you need in a variety of dosage levels, and some are even in chewable forms that taste good without adding to your overall sugar consumption.
Fu J, Han L, Zhao Y, et al. Vitamin D levels are associated with metabolic syndrome in adolescents and young adults: The BCAMS study. Clin Nutr. 2018 Sep 6. pii: S0261-5614(18)32435-X.
BACKGROUND AND AIMS: The relationship between vitamin D deficiency and metabolic syndrome (MS) remains controversial with relatively sparse data among youth. Therefore, we attempted to explicate the association of 25-hydroxyvitamin D [25(OH)D] levels with MS in Chinese adolescents and young adults.
METHODS: A cohort of 559 subjects at elevated risk of MS were recruited at 14-28 years of age as a follow-up to the Beijing Child and Adolescent Metabolic Syndrome Study. Subjects underwent clinical assessment including a 2h-oral glucose tolerance test. The concentrations of 25(OH)D, glucose, insulin and lipids were determined. MS was defined using the 2009 harmonized definition.
RESULTS: The prevalence of vitamin D deficiency (< 20 ng/ml) was 78.3%. After adjusting for age, gender and season, 25(OH)D concentrations were negatively correlated with neck circumference, percent body fat, LDL cholesterol, fasting and 2h-glucose levels (all P < 0.05). 25(OH)D levels were significantly lower in participants with obesity, high triglycerides, type 2 diabetes, or MS, compared to their respective counterparts (all P < 0.05). After adjusting for potential confounders (e.g., body mass index), participants in the lowest 25(OH)D tertile were 2.5 times more likely to exhibit MS than were those in the highest tertile (Odds Ratio: 2.48; 95% CI: 1.13-5.45, P < 0.05).
CONCLUSIONS: Vitamin D deficiency was very common in this young Chinese population at risk for MS. Given this association between low vitamin D levels and MS, the role of vitamin D supplementation in Chinese youths needs further examination, particular in those at risk for MS.