i.Effects of zinc in Pre-menstrual syndrome

Studies shows that low concentration of zinc in women can cause pre-menstrual
syndrome. Symptoms of pre-menstrual syndrome includes emotional, tension and fluid retention. These symptoms are experienced by women in the days right before menstruation. According to studies, PMS affects 50% of menstruating women, (Bhowmik & Chiranjib, 2010). It is also said that intake of zinc that is about or more than 15 mg/day showed a decrease risk of having PMS (Nierenberg,2013). Zinc regulates the secretion of hormones and progesterone and so low concentrations of zinc leads to a reduction in secretion of progesterone and endorphins. Women facing PMS was found with lower levels of zinc during the luteul phase of menstruation. Moreover, deficiencies of this mineral also co-relates to symptoms that is related to moods such as depression and menstrual cramps (Nierenberg,2013). With the help of zinc, it can increase blood flow or diminish inflammation in the uterus, preventing muscle cramps (Tremblay, 2018). According to the University of Maryland Medical Center, it is recommended to take multivitamins containing zinc in order to lessen premenstrual syndrome.

ii.Effects of zinc during pregnancy
Based on Roohani et al, 2013, reproductive events can be affected if a
pregnant woman is deficit of zinc, copper and magnesium. These reproductive events include infertility, pregnancy wastage, birth defects, pregnancy-induced hypertension, placental abruption, premature rupture membranes, fetal growth retardation, still birth and low birth weight. Sometimes birth defects can be identified before birth, at birth or in some cases later in infancy such as hearing defects or other kinds of defect (Kaur et al., 2014). Besides that, external defects of marginal status of zinc during pregnancy also affects the appearance of the child such as misshaped heads and fused or missing digits of the feet (King, 2000). The research looking into the effects of zinc on immune functions in a healthy pregnant woman showed that zinc induces the mitogenic influence on human lymphocytes exerting its greatest proliferative influence in concentrations which is more than those in normal human plasma. However, the proliferative responses of peripheral blood lymphocytes to zinc were reduced to the same level as the phytomitogen PHA. As pregnancy progresses, plasma level decreases and during birth, the micronutrient level of zinc induces together with the increase of metabolism in both mother and foetus (Raimi et al., 2012). Severe low intake of zinc gives impact to the duration of gestation which is the development of foetus and can lead to an increase of risk for preterm delivery (Kaur et al., 2014). During pregnancy, an additional of 100mg is needed as 57% of the zinc consumed is deposited in the foetus and 24% is used in the uterine muscle (King, 2000). This additional need can be fulfilled by increasing intake of zinc or adjusting zinc homeostasis. However, the adjustment of zinc homeostasis will be much more in women that takes up low intake of zinc in their diet. Based on King 2000, other factors such as smoking, alcohol abuse, acute maternal infections, strenuous exercise and high doses of supplemental iron can affect the capability to absorb or transport zinc to the foetus. Then, level of zinc in body also can influence zinc absorption as zinc deprived humans absorb zinc efficiently whereas those with high zinc diet does not absorb zinc well (Roohani, Hurrel, Kelishadi, & Schulin, 2013).
Another factor is the mechanism between copper and anti-copper action that prevents the intestinal absorption of copper and so those with Wilson’s disease should be given anti-copper therapy during pregnancy (Editorial, Page, ; Al, 1997; Kaur et al., 2014)Most of the time iron supplements are given to pregnant women. If zinc supplements are also given, there’s a possibility that the influence of iron supplements towards zinc status will be reduced and at the end risking the effect of being deficient of both nutrients (Brien, Zavaleta, Caulfield, Wen, & Abrams, 2018; Kaur et al., 2014).
In terms of lactation, those who started pregnancy with a marginal zinc status are usually zinc deficient as fetal growth requires an abundant concentration of zinc. So, these mothers will lack zinc in their system and it affects the level of zinc in their breast milk (Osredkar, 2011). Lactation describes the secretion of milk from the mammary glands and the duration when a mother lactates to feed her young. Premature infants are more susceptible to evolve zinc deficiency compared to a full-term infant as they have insufficient body storage for zinc and their ability to absorb zinc from the gut is defective. Generally, younger children require more nutrients as it is a critical stage for growth and so they are at risk of zinc deficiency. The first few months, babies require sufficient zinc from their mothers which is through breast feeding and then after that they can be fed by complementary foods containing absorbable zinc (Roohani et al., 2013).
As woman ages, the zinc status in their body decreases because they tend to eat less and the food they eat does not really have a large concentration of Zinc. Additionally, excess estrogen reduces zinc status. Zinc is needed at this point in order to slow down the progression of the disorder of retina (Bhowmik & Chiranjib, 2010).
4.0 Effect of high concentrations of zinc to human body
Zinc is type of mineral which must be taken in small amounts for good health as taking too much also has its downfall. There are three ways where zinc could have entered the human body which are through inhalation, through skin or through ingestion. Humans could be exposed to zinc-containing smoke especially when they are working or involved in the industrial processes like galvanization. Other than that, military smoke bombs consist of zinc oxide or zinc chloride that could be harmful to human when inhaled. Soldiers are usually the first to be exposed when it comes to smoke bombs. In some cases, soldiers could develop Adult Respiratory Distress Syndrome (ARDDS) and without proper treatment, it could lead to a certain death, (Plum et al., 2010). Being exposed to the smoke containing zinc oxide during the smelting or welding of zinc can also lead to Metal Fume Fever (MFF). However, the effect is not as life threatening and the respiratory effects will go away after a while.
In terms of dermal exposure, there are no proper evidence that it is harmful to the skin as lotions, ointments and other products consists of zinc substance.
Zinc ingestion does not affect the human body. However, zinc sulphate is toxic for the body. Additionally, too much of zinc intake could reduce the concentration of copper in the body. The recommended daily intake of zinc is roughly about 15 mg/day (Raimi, O.G., Falade, O. A., Folorunso, O. S. and Lawal & Department, 2012; Tapiero & Tew, 2003). Copper is mostly concentrated at areas in the body where metabolic activities are carried out such as kidneys, livers, heart and brain.