**8. Policy and best practices (supplementation/education)**

Vitamin D deficiency is very prevalent across the globe among pregnant women [245]. The range of recommended vitamin D from during pregnancy varies from 200 to 4000 IU/d worldwide. The American Pregnancy Association stated that pregnant women are recommended to have (100 μg/d) of vitamin D intake to reduce the risk of premature birth and infections which is a considerably higher amount of vitamin D compared to the recommended intake of 10 μg/d for women [246]. A daily intake of 600 IU is suggested during pregnancy in China to have healthy and balanced fetal growth [247]. In the United Kingdom, it is advised to have a maternal vitamin D intake of 400 IU/d. Switzerland follows the IOM dietary recommended nutrient intake. For pregnant/lactating women who are at risk of vitamin D deficiency, the advised vitamin D is 1500–2000 IU/d, and for women,

**51**

*Maternal Vitamin D Status among Different Ethnic Groups and Its Potential Contribution…*

without deficiency, the recommended intake is 600 IU [248]. The ministry of health of New Zealand recommended 200 IU/d dietary intake of vitamin D [249]. Vitamin D requirements are higher among pregnant women (average 400 IU/d), and it is very important to maintain optimum serum level of vitamin D during

WHO encourages receiving vitamin D from a healthy and balanced diet [250]. Some recent studies suggest vitamin D food fortification can work as a means to improve vitamin D status among the overall population, which can benefit pregnant women as well [251]. Currently, Canada, United States, India, and Finland had a vitamin D food fortification policy. In North America, the foods that are naturally enriched by vitamin D, such as fatty fish, are quite expensive and are not readily available to the general population. A majority of vitamin D intake comes from fortified food in North America. The United States has a voluntary fortification policy, and Canada has both voluntary and mandatory fortification policies for specific foods. In the United States, milk including fluid, acidified, cultured, skimmed powder, evaporated milk (1.05 μg/100 g), soy-based beverages (1.25 μg/100 g), soy products (2.23 μg/100 g), margarine (8.3 μg/100 g), butter alternatives spread (8.25 μg/100 g), cheese alternatives spread (6.25 μg/100 g), yogurt (2.22 μg/100 g), fortified fruit juice (2.5 μg/240 mL), meal replacement products (2.5 μg/40 g), cheese products (2.02 μg/30 g), and enriched ready to eat cereal (8.75 μg/100 g), rice, cornmeal, noodle, macaroni (2.25 μg/100 g), farina (8.75 μg/100 g), and instant formula (1–25 μg/100 kcal) are vitamin D fortified [252]. Mandatory fortified products in Canada are margarine (1.5 μg/10 g), infant formulas (10 μg /L), milk (powder, sterilized, flavored, skim, evaporated) (2.5 μg/250 mL), meal replacements (5% of DV/55 g), soy beverages, and soy beverage products (1.5–3 μg/250 mL) [253]. Some recent studies have shown a high prevalence of vitamin D inadequacies despite the mandatory fortification. The Department of Health, the Government of Canada, recently announced that vitamin D fortification levels need to be increased to alleviate the risk of rickets in children and osteomalacia in adults. It proposed that by the end of December 2022, vitamin D level in cow's milk, and goat's milk will be increased to 2 μg/100 ml (current range 0.9–1.2 μg/100 ml) and in margarine, it will be increased 26 μg/100 g (current range 13.3–17.5 μg/100 g) [254]. Fluid milk (2.5 μg/250 mL) and margarine (2 μg/10 g) are also fortified in Finland that had helped the general Finish population to improve vitamin D status. Similar to the United States, Canada fortification policy, edible oil, margarine (0.55 μg/10 g), cow's milk (1.25 μg/250 mL), and ready to eat cereals (5 μg/1/2-¾ cups) are fortified in Australia [255]. Similar approaches can be adopted by other countries to improve vitamin D inadequacy

*DOI: http://dx.doi.org/10.5772/intechopen.90766*

maternity and for the fetus growth.

among pregnant women as well as the general population.

Supplement intake can also play an important role in improving vitamin D status among pregnant and lactating women. A recent study assessing maternal vitamin D inadequacies showed that vitamin D supplementation of ≤2000 IU/d minimizes the chance of neonatal mortality [256]. Taking a vitamin D supplement may also reduce the risk of PET, GDM, and low birth weight during pregnancy [257]. The current WHO guideline recommends 200 IU/d of vitamin D supplement intake among pregnant women with vitamin D deficiency to reduce the risk of PET, low birth weight, and preterm birth [258]. In Turkey, free supplementation of vitamin D (1200 IU/d) is provided to all women from early pregnancy to 6 months after delivery [259]. In Canada, pregnant women are suggested to take a vitamin D supplement of 400–600 IU/d [260]. A similar vitamin D supplementation intake approach (400 IU/d) is followed in New Zealand as well during pregnancy The United Kingdom Health Department provides free vitamin D supplementation to pregnant women and newborn children and recommends taking 10 μg (400 IU) of

#### *Maternal Vitamin D Status among Different Ethnic Groups and Its Potential Contribution… DOI: http://dx.doi.org/10.5772/intechopen.90766*

without deficiency, the recommended intake is 600 IU [248]. The ministry of health of New Zealand recommended 200 IU/d dietary intake of vitamin D [249]. Vitamin D requirements are higher among pregnant women (average 400 IU/d), and it is very important to maintain optimum serum level of vitamin D during maternity and for the fetus growth.

WHO encourages receiving vitamin D from a healthy and balanced diet [250]. Some recent studies suggest vitamin D food fortification can work as a means to improve vitamin D status among the overall population, which can benefit pregnant women as well [251]. Currently, Canada, United States, India, and Finland had a vitamin D food fortification policy. In North America, the foods that are naturally enriched by vitamin D, such as fatty fish, are quite expensive and are not readily available to the general population. A majority of vitamin D intake comes from fortified food in North America. The United States has a voluntary fortification policy, and Canada has both voluntary and mandatory fortification policies for specific foods. In the United States, milk including fluid, acidified, cultured, skimmed powder, evaporated milk (1.05 μg/100 g), soy-based beverages (1.25 μg/100 g), soy products (2.23 μg/100 g), margarine (8.3 μg/100 g), butter alternatives spread (8.25 μg/100 g), cheese alternatives spread (6.25 μg/100 g), yogurt (2.22 μg/100 g), fortified fruit juice (2.5 μg/240 mL), meal replacement products (2.5 μg/40 g), cheese products (2.02 μg/30 g), and enriched ready to eat cereal (8.75 μg/100 g), rice, cornmeal, noodle, macaroni (2.25 μg/100 g), farina (8.75 μg/100 g), and instant formula (1–25 μg/100 kcal) are vitamin D fortified [252]. Mandatory fortified products in Canada are margarine (1.5 μg/10 g), infant formulas (10 μg /L), milk (powder, sterilized, flavored, skim, evaporated) (2.5 μg/250 mL), meal replacements (5% of DV/55 g), soy beverages, and soy beverage products (1.5–3 μg/250 mL) [253]. Some recent studies have shown a high prevalence of vitamin D inadequacies despite the mandatory fortification. The Department of Health, the Government of Canada, recently announced that vitamin D fortification levels need to be increased to alleviate the risk of rickets in children and osteomalacia in adults. It proposed that by the end of December 2022, vitamin D level in cow's milk, and goat's milk will be increased to 2 μg/100 ml (current range 0.9–1.2 μg/100 ml) and in margarine, it will be increased 26 μg/100 g (current range 13.3–17.5 μg/100 g) [254]. Fluid milk (2.5 μg/250 mL) and margarine (2 μg/10 g) are also fortified in Finland that had helped the general Finish population to improve vitamin D status. Similar to the United States, Canada fortification policy, edible oil, margarine (0.55 μg/10 g), cow's milk (1.25 μg/250 mL), and ready to eat cereals (5 μg/1/2-¾ cups) are fortified in Australia [255]. Similar approaches can be adopted by other countries to improve vitamin D inadequacy among pregnant women as well as the general population.

Supplement intake can also play an important role in improving vitamin D status among pregnant and lactating women. A recent study assessing maternal vitamin D inadequacies showed that vitamin D supplementation of ≤2000 IU/d minimizes the chance of neonatal mortality [256]. Taking a vitamin D supplement may also reduce the risk of PET, GDM, and low birth weight during pregnancy [257]. The current WHO guideline recommends 200 IU/d of vitamin D supplement intake among pregnant women with vitamin D deficiency to reduce the risk of PET, low birth weight, and preterm birth [258]. In Turkey, free supplementation of vitamin D (1200 IU/d) is provided to all women from early pregnancy to 6 months after delivery [259]. In Canada, pregnant women are suggested to take a vitamin D supplement of 400–600 IU/d [260]. A similar vitamin D supplementation intake approach (400 IU/d) is followed in New Zealand as well during pregnancy The United Kingdom Health Department provides free vitamin D supplementation to pregnant women and newborn children and recommends taking 10 μg (400 IU) of

*Vitamin D Deficiency*

**status**

conducted in 487 mother-child pairs revealed that children born to mothers in the high 25(OH)D tertile (>50.7 nmol/l) had decreased risk of developing ADHD-like symptoms at 4 years of age, compared to children of women in the low 25(OH)D tertile (<38.4 nmol/l) [231]. In another prospective study conducted in 1650 mother-child pairs, Morales et al. found an inverse association between maternal circulating levels of 25(OH)D in pregnancy and risk of developing ADHD-like at ages 4–5 years [232]. Using a case-control design study, Chen and colleagues reported that low maternal first-trimester serum levels of 25(OH)D was associated with increased odds of ASD diagnosis at age 3–7 years in the offspring [233]. Another study also found an increased risk of ASD in children who were born to mothers with vitamin D deficiency at mid-gestation [234]. In a large populationbased cohort of mothers and their children, gestational vitamin D deficiency was associated with a continuous measure of autism-related traits at 6 years [235]. Magnusson et al. also observed a relationship between maternal vitamin D deficiency and risk of ASD with, but not without, intellectual disability [236]. Further, it has been demonstrated that low maternal vitamin D levels are associated with increased risk of schizophrenia within the subgroup of black but not white individuals [237]. Although more robust studies needed, these results highlight the importance of maternal vitamin D status in offspring brain development and function.

**7. The association of maternal vitamin D status and child vitamin D** 

Several lines of evidence suggest that there is a strong association between maternal 25(OH)D levels during pregnancy and newborn 25(OH)D concentrations at birth or in the early neonatal period [238–242]. Novakovic et al. reported that maternal circulating 25(OH)D levels were the most significant regulator of neonatal circulating vitamin D concentrations, even over the impact of genetic factors [243]. In another study, maternal characteristics explained 12.2%, and maternal 25(OH)D concentrations explained 32.1% of the neonatal vitamin D variance [13]. These results were confirmed in a systematic review reporting the range of correlation coefficients between maternal and newborn 25(OH)D concentrations, by region: European 0.42–0.95, America 0.68–0.97, Western Pacific 0.19–0.85, South-East Asian 0.78–0.81, and Mediterranean 0.03–0.88 [106]. Therefore, since maternal vitamin D status in pregnancy is an important determinant of neonatal 25(OH)D concentrations, attention should be given not only to vitamin D-deficient pregnant women, but also to

their newborns, especially if they are exclusively breast-fed [244].

**8. Policy and best practices (supplementation/education)**

Vitamin D deficiency is very prevalent across the globe among pregnant women [245]. The range of recommended vitamin D from during pregnancy varies from 200 to 4000 IU/d worldwide. The American Pregnancy Association stated that pregnant women are recommended to have (100 μg/d) of vitamin D intake to reduce the risk of premature birth and infections which is a considerably higher amount of vitamin D compared to the recommended intake of 10 μg/d for women [246]. A daily intake of 600 IU is suggested during pregnancy in China to have healthy and balanced fetal growth [247]. In the United Kingdom, it is advised to have a maternal vitamin D intake of 400 IU/d. Switzerland follows the IOM dietary recommended nutrient intake. For pregnant/lactating women who are at risk of vitamin D deficiency, the advised vitamin D is 1500–2000 IU/d, and for women,

**50**

vitamin D supplements during pregnancy and lactation [261]. Taking vitamin D enriched food and supplement can be advised to maintain optimum serum levels during pregnancy.
