Both mother and fetus need sufficient nutrition. The first 1000 days of life is a crucial period in pregnancy and nutrition plays a significant influence on the growth and development of a child in this period. Good nutrition can be obtained from sufficient macronutrients and micronutrients in the body. Micronutrients can be obtained from minerals and vitamins contained in food and supplements. Micronutrient deficiency still becomes a serious issue for women of reproductive age, especially pregnant women. This issue is quite common in developing countries. One of the micronutrient deficiencies is vitamin D. 1,2
Vitamin D is a fat-soluble vitamin that can be obtained from some food sources including milk, fish, and eggs, but only in small amounts.1 Vitamin D is also produced and activated in the body through exposure to sunlight.1,2 Generally, vitamin D mostly can be obtained from vitamin D3 supplements. Vitamin D is divided into vitamin D2 (Ergocalciferol) which is found in many foods, vitamin D3 (Cholecalciferol) which is a measurable form to increase body vitamin D levels obtained from supplements, Calcidiol or serum 25-hydroxyvitamin-D ( 25-OH-D) which is a measured parameter of vitamin D levels in the body, and calcitriol which is the active form found in blood plasma.1,2 The main mechanism of action of vitamin D is the metabolism of calcium and phosphorus which are beneficial for bone mineralization. However, vitamin D has receptors spread almost throughout the body. Therefore, besides calcium and phosphorus metabolism, vitamin D also has an important role in the immune system. A deficiency of vitamin D can cause various health problems such as allergies, autoimmune, and cancer. 1,2,3
The measurement of Vitamin D levels can be through serum concentrations of 25-OH-D as an indicator of vitamin D status in the body. A minimum vitamin D level of 20 ng/ml is needed to avoid bone disorders, but with various metabolic interactions in the body, it is considered to be deficient in vitamin D if the serum 25-OH-D level is lower than 32 ng/ml. Currently, vitamin D deficiency still becomes a global issue and is mostly experienced by pregnant women.1,3 Vitamin D deficiency in pregnancy mostly occurs in a population with high risk such as vegetarians, women who rarely sunbathe or have limited access to sunlight, and are black race. 4 Pregnant women need vitamin D as Vitamin D levels in newborns depend on vitamin D levels during pregnancy. Thus, if pregnant women have a low Vitamin D level, it can also affect the fetus or baby 3,4
Vitamin D deficiency is associated with various disorders and health problems considering that vitamin D receptors are found in almost all parts of the body such as the reproductive tract, ovaries, endometrium, and placenta.5 Serum levels of vitamin D in pregnant women have decreased during pregnancy due to the increased physiological needs of the fetus. Vitamin D levels will be needed more along with the age of the gestation period. In the 2nd and 3rd trimesters of pregnancy, the need for vitamin D will increase.3,4,5
In pregnancy, vitamin D deficiency is associated with various problems in both the mother and fetus. For mothers, this can increase the risk of hypertension in pregnancy, premature birth, and diabetes in pregnancy, while for the fetus, it can increase the risk of low birth weight, and bone mass abnormalities which can lead to several diseases such as rickets and fractures in newborns, attention deficit hyperactive disorder behavior (ADHD) and autism. 3,4
The recommended dose of vitamin D is different for each person. However, adults in general can regularly consume 1000-4000 IU per day. 2,4,6 Pregnant women are recommended to get vitamin D supplements of 400 -600 IU per day. The administration of vitamin D at a dose of 1000-4000 IU per day is considered safe and has an effect.2-7 Research conducted states that consumption of vitamin D at a dose of 4000 IU per day for 6 months in pregnant women is considered safe and provides good benefits. Indeed, consuming vitamin D should be done by checking the initial serum vitamin D level in the body and checking it periodically within 3 months to see changes in the body's vitamin D levels for adjustment.1-7 Routine vitamin D administration is safe since early pregnancy. Clinical studies reveal that no toxicity occurs with the use of 30,000 IU of vitamin D3 per day as long as the serum vitamin D level is below 200 ng/ml.1,3
Conclusion
Vitamin D supplementation at a dose of 1000-4000 IU per day for pregnant women is considered safe and can provide good benefits to both the pregnant woman and the fetus or child. [1] The provision of vitamin D supplements in pregnancy has been proven to improve fetal growth and reduce the risk of low birth weight, hypertension in pregnancy, premature birth, and gestational diabetes. Besides, pregnant women with sufficient levels of vitamin D contribute to the reduced incidence of enamel defects in their babies as well as a reduced risk of attention deficit hyperactive disorder (ADHD) and autism.1-7
References
1. Bi WG, Nuyt AM, Weiler H, Leduc L, Santamaria C, Wei SQ. Association between vitamin D supplementation during pregnancy and offspring growth, morbidity, and mortality: A Systematic Review and Meta-analysis. JAMA Pediatr. 2018
2. Mousa A, Naqash A, Lim S. Macronutrient and Micronutrient Intake during Pregnancy: An Overview of Recent Evidence. Nutrient. 2019; 11(2).
3. Lopez P, Faustino R, Stefan P, Peter C. Vitamin D supplementation during pregnancy: an overview. Current Opinion in Obstetrics and Gynecology. 2020; 32(5):316-321
4. ACOG Committee. Vitamin D: Screening and supplementation during pregnancy. Obstet Gynecol. 2011; 118(1): 197-198.
5. Franasiak JM, Lara E, Pellicer A. Vitamin D in human reproduction. Current Opinion in Obstetrics and Gynecology. 2017; 29(4):189-194.
6. Mithal A, Kalra S. Vitamin D supplementation in pregnancy. Indian J Endocrinol Metab. 2014; 18(5): 593-596.
7. Sass L, Vinding RK, Stokholm J. Pregnancy and Neurodevelopment in Childhood. JAMA Netw Open. 2020; 3(12)
