Brief observation

Vitamin D insufficiency among free-living healthy young adults

The role of circulating 25-hydroxyvitamin D (25(OH)D) in the prevention of early-onset colorectal cancer (CRC) in young adults aged <50 years is uncertain. We evaluated the age-stratified associations (<50 vs ≥50 years) between circulating 25(OH)D levels and the risk of CRC in a large sample of Korean adults.

Our cohort study included 236,382 participants (mean age, 38.0 [standard deviation, 9.0] years) who underwent a comprehensive health examination, including measurement of serum 25(OH)D levels. Serum 25(OH)D levels were categorized as <10, 10 to 20, and ≥20 ng/mL. CRC, along with the histologic subtype, site, and invasiveness, was ascertained through linkage with the national cancer registry. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CRC according to the serum 25(OH)D status, with adjustment for potential confounders.

During the 1,393,741 person-years of follow-up (median, 6.5 years; interquartile range, 4.5–7.5 years), 341 participants developed CRC (incidence rate, 19.2 per 10⁵ person-years). Among young individuals aged <50 years, serum 25(OH)D levels were inversely associated with the risk of incident CRC with HRs (95% CIs) of 0.61 (0.43–0.86) and 0.41 (0.27–0.63) for 25(OH)D 10 to 19 ng/mL and ≥20 ng/mL, respectively, with respect to the reference (<10 ng/mL) (P for trend <.001, time-dependent model). Significant associations were evident for adenocarcinoma, colon cancer, and invasive cancers. For those aged ≥50 years, associations were similar, although slightly attenuated compared with younger individuals.

Serum 25(OH)D levels may have beneficial associations with the risk of developing CRC for both early-onset and late-onset disease.

Comparar los niveles de vitamina D maternos con la zona de residencia o el consumo de pescado, así como su relación con el peso, la longitud y el perímetro craneal de los bebés.

Cohorte de 100 parejas madre-hijo (n = 100) de la provincia de Sevilla (Hospital Universitario Virgen del Rocío y Hospital Universitario de Valme). En muestras de sangre materna (edad gestacional ≥ 40 semanas) se han medido los niveles de 25(OH)D mediante quimioluminiscencia. Las medidas antropométricas de los bebés se realizaron mediante métodos estándares.

Con relación a los niveles de vitamina D, 54% presentaban valores deficientes, 26% insuficientes y 20% valores suficientes. Tras un análisis de regresión múltiple, se observa que no hay diferencia significativa entre niveles de vitamina D maternos, la longitud y el perímetro cefálico de los bebés, sin embargo, sí con el peso al nacer (p < 0,05). Al aplicarse la T-Student y el test Wilcoxon, no hay relación entre niveles de vitamina D y el área de residencia ni con el consumo de pescado materno (ambos p > 0,05).

El 80% de madres presentan valores deficientes e insuficientes de vitamina D. No hay correlación entre este parámetro y la longitud y perímetro cefálico del bebé, observándose correlación negativa con el peso al nacer. Tampoco se observa correlación entre la zona de residencia o el consumo de pescado y niveles de vitamina D en madres. Sugerimos complementos en dieta de madres gestantes y seguimiento de los niveles de vitamina D en los bebés.

To compare maternal vitamin D levels with the area of residence or the consumption of fish, as well as its relationship with the weight, length and cranial perimeter of babies.

Cohort of 100 mother–child pairs (n = 100) from the province of Seville (Virgen del Rocío University Hospital and Valme University Hospital). In maternal blood samples (gestational age ≥ 40 weeks) 25(OH)D levels have been measured by chemiluminescence. Anthropometric measurements of the babies were made using standard methods.

Regarding vitamin D levels, 54% had deficient values, 26% insufficient and 20% sufficient values. After a multiple regression analysis, it is observed that there is no significant difference between maternal vitamin D levels, the length and the cephalic perimeter of the babies, however, there is a difference with the birth weight (P < .05). When applying the t-Student and the Wilcoxon test, there is no relationship between vitamin D levels and the area of residence or with maternal fish consumption (both P > .05).

Eighty percent of mothers present deficient and insufficient values of vitamin D. There is no correlation between this parameter and the length and cephalic perimeter of the baby, observing a negative correlation with birth weight. No correlation was observed between the area of residence or the consumption of fish and vitamin D levels in mothers. We suggest dietary supplements for pregnant mothers and monitoring of vitamin D levels in babies.

Vitamin D is the sunshine vitamin. During exposure to sunlight, 7-dehydrocholesterol in the skin absorbs ultraviolet B (UVB) radiation converting it to previtamin D3. Previtamin D3 being thermodynamically unstable isomerizes within a few hours to form vitamin D3. Prolonged exposure to UVB leads to transformation into tachysterol or lumisterol, which can be further metabolized to biologically active hydroxyforms. A multitude of factors affect its synthesis including skin pigmentation, time of day, season, latitude, altitude, and sunscreen use. The body has a large capacity to produce vitamin D₃, and sensible sun exposure can be effective in helping to maintain blood levels of 25-hydroxyvitamin D. Exposure to sunlight also provides other health-related benefits that are independent of vitamin D production. These include activation of central neuroendocrine mediators including activation of hypothalamus-pituitary-adrenal axis (HPA) or its elements and production of nitric oxide. The latter would lead to a reduction of blood pressure. The goal of this chapter is to provide a broad overview on the role of sunlight in providing vitamin D and other health benefits including action of pro-vitamin D3 derivatives or vitamin D-independent effects.

The current study aimed to assess the effect of fortified yogurt with nano-encapsulated vitamin D on serum pro-oxidant anti-oxidant balance (PAB) in adults with or without metabolic syndrome.

In a quadruple blind clinical trial study, 139 adults with an age range of 30–50 years were randomly selected to receive either 1500 IU nano-encapsulated vitamin D fortified yogurt or placebo for ten weeks. Before and after the intervention period, blood sample was taken to determine the serum levels of vitamin D, pro-oxidant-antioxidant balance (PAB), and high-sensitivity C-reactive protein (hs-CRP). The laboratory tests were checked at baseline and at the end of the treatment.

Serum vitamin D increased significantly, from 14.47 ± 6.07 ng/mL to 21.39 ± 6.54 ng/mL (P < 0.001) after ten weeks in the intervention group. Serum hs-CRP and PAB were significantly lower following consumption period in intervention group [1.95(0.4–8.15) g/dL vs. 1.35(0.25–3.62) g/dL; P = 0.013] and (135.19 ± 42.4 HK vs. 115.39 ± 44.69) HK; P = 0.018] respectively. There were no significant differences between the intervention and control groups regarding weight and BMI at the end of the intervention period (p > 0.05).

Low-fat yogurt fortified with nano-encapsulated vitamin D was found to reduce serum PAB levels in adults with metabolic syndrome.

The findings of the present study indicated that a low-fat yogurt fortified with 1500 IU nano-encapsulated vitamin D for ten weeks, leads to a significant reduction in serum hs-CRP and PAB concentrations highlighted the anti-inflammatory/anti-oxidative effect of vitamin D.