Vitamin D Deficiency During Pregnancy

Why Is Vitamin D Important in Pregnancy?

Vitamin D is a fat-soluble vitamin and a key modulator of calcium metabolism. During pregnancy, the calcium demands increase in the third trimester. Vitamin D is essential for maternal health, fetal skeletal growth, and optimal maternal and fetal outcomes.

The two types of vitamin D include,

• Vitamin D3 (Cholecalciferol) - Is generated in the skin by exposure to sunlight.

• Vitamin D2 (Ergocalciferol) - Is derived from plant sources.

Both types of vitamin D can be absorbed in the gut. In addition, vitamin D is present in fish and some plants but is not found in significant amounts in meat, poultry, dairy, or commonly eaten fruits and vegetables.

How Much Vitamin D Does a Pregnant Woman Need?

The food and nutrition board recommends that an adequate vitamin D intake is 600 IU per day for both pregnant and nonpregnant women aged up to 50 years. Most prenatal vitamins for pregnant women contain 400 IU of vitamin D per tablet.

What Foods Are Rich in Vitamin D?

The following foods are rich in vitamin D-

• Fish liver oil (cod liver oil).

• Fatty fish.

• Eggs.

• Salmon.

• Fortified foods like milk, bread, cheeses, cereals, and yogurts.

However, the relative contribution of dietary vitamin D is low in humans compared with endogenous production of vitamin D from sunlight.

What Are the Various Stages of Vitamin D Deficiency During Pregnancy?

Vitamin D status is determined by measuring plasma 25(OH)D level. The healthy range is 44 to 70 ng/mL. However, levels more than 32 ng/mL are considered adequate.

The following table shows the stages of vitamin D deficiency and associated maternal and fetal outcomes:

What Are the Risk Factors for Vitamin D Deficiency During Pregnancy?

The following factors can increase the risk of vitamin D deficiency in pregnant women:

• Obesity - High body fat levels can limit the body's ability to absorb vitamin D from the skin.

• People with darker skin tones (with more melanin pigment on the skin) have less vitamin D production in the skin.

• Smoking.

• Low dietary vitamin D intake, especially vegetarian diet.

• Medications like steroids, cholesterol-lowering drugs, anti-seizure medications, or diuretics interfere with vitamin D absorption.

• Disorders like Crohn's disease or celiac disease involve a decreased ability to absorb dietary fat, leading to less vitamin D absorption.

• Malabsorptive syndromes like cystic fibrosis, cholestatic liver disease, inflammatory bowel disease, and short gut syndrome.

• Extensive skin covered by clothes.

• Northern latitudes (winter or springtime).

• Limited exposure to the sun.

• Regular use of sunscreens.

• Aging- The ability of the skin to synthesize vitamin D decreases with age.

What Are the Symptoms and Effects of Vitamin D Deficiency During Pregnancy?

Inadequate levels of vitamin D in pregnant women may lead to the following outcomes,

1. Symptoms of Vitamin D Deficiency in Mother:

• Preeclampsia (high blood pressure during pregnancy) and hypertensive disorders.

• Bone pains.

• Muscle aches (myalgia).

• Weakness.

• Softened bones.

2. Effects of Vitamin D Deficiency on the Fetus and Newborn:

• Infant size is lesser than normal.

• Low birth weight babies.

• Poor skeletal mineralization leads to conditions like congenital rickets, osteopenia (loss of bone mineral density), or craniotabes (softening of skull bones).

• Impaired fetal bone ossification.

• Larger fontanelles (impaired skull ossification).

3. Vitamin D Deficiency During Lactation:

• Babies who are extensively breastfed are at a higher risk of vitamin D deficiency because human milk contains very low levels of vitamin D. However, formula-fed babies receive optimum amounts of 400 IU of vitamin D per liter.

• Breast-fed infants from vitamin D deficient mothers can sometimes manifest life-threatening conditions like hypocalcemic seizures and dilated cardiomyopathy.

4. Effects of Vitamin D Deficiency in Childhood:

• Asthma.

• Type 1 diabetes mellitus.

How to Get a Sufficient Amount of Vitamin D During Pregnancy?

Vitamins and minerals are an essential part of a pregnant woman's diet. Following dietary and lifestyle changes can be made to cope with the deficiency of vitamin D-

• Daily sunbathing for at least 10 minutes to 30 minutes of midday sunlight.

• Diet can include- oily fishes (salmon, sardines, mackerel, or herring), eggs, mushrooms, or meat.

• Eating fortified breakfast cereals, bread, cheeses, and dairy products.

• Prenatal vitamins as recommended by doctors.

What Happens in Vitamin D Toxicity During Pregnancy?

The highest daily dose that can be given in pregnancy is 4,000 IU/day. Excessive vitamin D intake during pregnancy can result in the risk of hypercalcemia in the fetus.

Conclusion:

Vitamin D plays a very vital role in the human body. It is responsible for maintaining healthy bones and teeth and regulating inflammation and the body's immune function. The demand for vitamins and minerals increases as the baby grows inside the mother during pregnancy. Therefore, a pregnant mother must take special care of her nutrition. A pregnant woman must take her prenatal vitamins and supplements as prescribed by the doctors. Vitamin D deficiency can cause very severe maternal and fetal outcomes. Thus, maintaining adequate vitamin D levels through diet, daily exposure to sunlight, and vitamin D supplements are essential for a healthy pregnancy and a baby's growth and development. The vitamin D levels should be checked at regular intervals during pregnancy so that doctors can prescribe the required supplements.