Vitamin D activity of breast milk in women randomly assigned to vitamin D3 supplementation during pregnancy.

BACKGROUND: Human milk is typically low in vitamin D activity (VDA). Whether the vitamin D content of breast milk at birth can be increased by supplementing the mother during pregnancy has not been reported to the best of our knowledge. OBJECTIVE: We examined the effect of vitamin D supplementation during pregnancy on breast-milk VDA in the first 2 mo of lactation. DESIGN: Breast-milk samples were obtained from women who were enrolled in a randomized, double-blinded, placebo-controlled trial of vitamin D supplementation during pregnancy. Pregnant women were enrolled at 27 wk of gestation and randomly assigned to the following 3 groups: a placebo group, a group who received one dosage of daily oral vitamin D3 (1000 IU), or a group who received 2 dosages of daily oral vitamin D3 (2000 IU). Serum 25-hydroxyvitamin D [25(OH)D] was measured at enrollment, at 36 wk of gestation, and in cord blood at birth. Study participants who were breastfeeding were invited to provide breast-milk samples for VDA measurement [concentration of vitamin D2, vitamin D3, 25(OH)D2, and 25(OH)D3] at 2 wk and 2 mo postpartum. A linear mixed model was used to compare breast-milk VDA between the 3 study groups. RESULTS: A total of 75 women provided breast-milk samples (44 women provided breast-milk samples at both 2 wk and 2 mo postpartum). The mean (95% CI) VDA at age 2 wk was 52 IU/L (12, 217 IU/L) in the placebo group, 51 IU/L (17, 151 IU/L) in the 1000-IU group, and 74 IU/L (25, 221 IU/L) in the 2000-IU group; and at age 2 mo, the mean (95% CI) VDA was 45 IU/L (16, 124 IU/L), 43 IU/L (18, 103 IU/L), and 58 IU/L (15, 224 IU/L), respectively. There was no significant interaction in VDA between the sample-collection time and treatment (P = 0.61), but there was a difference between lower- and higher-dosage treatment groups (P = 0.04). CONCLUSION: Maternal vitamin D supplementation during pregnancy of 2000 IU/d (compared with 1000 IU/d and with a placebo) results in a higher VDA of breast milk ≥2 mo postpartum. This trial was registered at the Australian New Zealand Clinical Trials Registry as ACTRN12610000483055.

Vitamina D, determinante de la salud ósea y extra ósea; importancia de su suplementación en la leche y derivados / Vitamin D, determinant of bone and extrabone health. Importance of Vitamin D supplementation in milk and dairy products

La vitamina D se obtiene fundamentalmente a partir de la irradiación ultravioleta en la piel del 7-dehidrocolesterol para formar colecalciferol (vitamina D3) y mínimamente por la dieta, salvo que se tomen alimentos fortificados en vitamina D, fundamentalmente leche; en algunos países se emplea ergocalciferol (vitamina D2). En el hígado la vitamina D3 se hidroxila para formar 25-hidroxivitamina D3 (marcador del estatus nutricional corporal en vitamina D). La 25OHD3, se hidroxila para formar 1,25-dihidroxivitamina D3 (1,25OH)2D3 en el riñón, para controlar la homeostasis del calcio y la salud del hueso y en otras células o tejidos, mediante el estímulo del VDR, incluyendo piel, músculo, los sistemas cardiovascular e inmune, homeostasis de la glucosa, y proliferación celular en general; de tal manera, que alrededor del 3% del genoma humano está regulado por la hormona 1,25(OH)2 vitamina D3. Estudios de asociación describen acciones beneficiosas a nivel cardiovascular, hipertensión arterial, cáncer colorectal, de mama, esclerosis múltiple, función inmune e inflamación etc. Un objetivo mínimo irrenunciable, para la salud pública, debe ser conseguir niveles séricos de 25OHD superiores a 20 ng/ml, para asegurar un estatus óptimo para la salud ósea y preferiblemente mayor de 30 ng/ml, si nos proponemos alcanzar otros objetivos. 'Paradójicamente' en España se da una elevada prevalencia de insuficiencia o incluso franca deficiencia de vitamina D en niños y jóvenes, persiste en adultos, en mujeres postmenopáusicas (osteoporóticas o no), o ancianos que viven en sus casas, y que es mayor si viven en residencias, con una variación estacional que apenas llega a normalizar los niveles séricos de 25OHD después del verano-otoño. También se ha demostrado una elevada prevalencia de niveles inadecuados de vitamina D en mujeres posmenopáusicas en tratamiento por osteoporosis con niveles de 25-hidroxivitamina D menores de 30 ng/ml y 20 ng/ml en el 63 y 30% respectivamente, lo que constituye un importante factor contribuyente a falta respuesta ósea al tratamiento. Una adecuación de niveles séricos de vitamina D, permitiría que la dieta proporcionara el calcio necesario para conseguir una buena salud ósea. Dada la dificultad para conseguir niveles adecuados de vitamina D por irradiación UV y por dieta, la suplementación adecuada de leche y derivados con vitamina D supone una atractiva posibilidad y un reto, para la Salud Pública de España y la Unión Europea, que ha dado excelentes resultados en EEUU, Canadá, Países de Norte de Europa, etc (AU)

Vitamin D is obtained mainly from ultraviolet irradiation of 7-dehydrocholesterol in the skin to form cholecalciferol (vitamin D3), and minimally from diet, unless vitamin D fortified food is taken, mainly enriched milk. In some countries, vitamin D is added to diet as ergocalciferol (vitamin D2). In the liver, vitamin D3 is hydroxylated to form 25-hydroxyvitamin D3 (marker of body nutritional status of vitamin D). Subsequently, in the kidney, 25OHD3 is hydroxylated to form 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). By VDR stimulation, (1,25)OH)2D3 controls calcium homeostasis and bone health and, what is more, many other cells and tissues including skin, muscle, cardiovascular and immune systems as well as glucose homeostasis. Thus, about 3% of the human genome is regulated by this hormone. Association and recent intervention studies describe beneficial effects on bone, cardiovascular disease, hypertension, diabetes mellitus type 2,colorectal cancer, breast cancer, multiple sclerosis, immune function inflammation etc. A minimum target for public health should be to achieve serum 25OHD levels above 20 ng/ml to ensure optimum status for bone health. However, levels above 30 ng/ml should be reached to achieve other health goals. Paradoxically, inadequacy (or even deficiency) in vitamin D levels is highly prevalent in children and youth in Spain. This deficit persists in adults, as well as in postmenopausal women (osteoporotic or not) and the elderly (especially amongst those institutionalized). Seasonal variation barely normalizes serum 25OHD levels after summer-autumn. Treated postmenopausal osteoporotic women also show high prevalence of inadequate levels of vitamin D, a major contributor to antiresortive treatments failure. A normalization of serum vitamin D enables diet to provide the calcium necessary to achieve a good bone health and an adequate response to antiresortive drugs. Given the difficulty to get adequate levels of vitamin D by UV irradiation and diet, a proper supplementation of milk with vitamin D is an attractive chance and a challenge for Public Health of Spain and the European Union. It has provided excellent results in the US, Canada, Northern Europe Countries, etc (AU)

Overreporting of vitamin D deficiency with the Roche Elecsys Vitamin D3 (25-OH) method.

BACKGROUND: Vitamin D deficiency is common. Recently Roche Diagnostics removed their Elecsys Vitamin D3 (25OH) electrochemiluminescence immunoassay (ECLIA) from use, citing deteriorating traceability to the reference method (liquid chromatography tandem mass spectrometry; LCMSMS). We investigated the performance of the Roche assay (2 assay formulations) against an LCMSMS method and the widely used DiaSorin radioimmunoassay (RIA) method. METHODS: Two sets of samples from separate populations were assayed for vitamin D. The first set was assayed using three different methods: RIA (DiaSorin) in 2004, polyclonal ECLIA (Roche) in early 2009 and LCMSMS in early 2010. The second set was assayed using polyclonal and monoclonal ECLIA (Roche) and LCMSMS in mid-2010. RESULTS: The correlation of the polyclonal ECLIA with the RIA was poor (ECLIA = 0.45 × RIA + 19, r(2) = 0.59, n = 773). LCMSMS results correlated with RIA (RIA = 0.86 × LCMSMS + 4, r(2) = 0.69, n = 49) better than with polyclonal ECLIA (polyclonal ECLIA = 0.55 × LCMSMS + 6, r(2) = 0.62, n = 55) despite a storage interval of 6 years.In recently collected samples monoclonal and polyclonal immunoassays gave similar results (monoclonal ECLIA = 0.93 polyclonal ECLIA -3, r(2) = 0.60, n = 153). The correlation between monoclonal Roche ECLIA and LCMSMS in these samples was very poor (monoclonal ECLIA = 0.31 × LCMSMS + 23, r(2) = 0.27). CONCLUSIONS: At the time of its removal from the market, the Roche Elecsys Vitamin D3 (25OH) assay showed unacceptable performance, underestimating vitamin D levels. It seems that this bias preceded the introduction of the monoclonal assay. The worldwide distribution of the assay and the duration of this bias likely led to a significant number of patients starting supplementation unnecessarily.