Vitamin D and Pregnancy

It is vital that women eat a diet that is healthy and varied when they are pregnant, obtaining all the necessary vitamins and minerals. However, some of these vitamins and minerals are even more important. Folic acid and vitamin D are specifically vital during pregnancy.

The Role of Vitamin D in Pregnancy

Vitamin D’s role is to regulate phosphate and calcium levels in the body. These are two elements needed for healthy teeth and bones. If you do not have sufficient vitamin D levels when you are pregnant (or when you are breastfeeding), the baby will not receive sufficient phosphate and calcium either, leading to weak bones and teeth. Some may even develop rickets.

But vitamin D does even more. It prevents some cancers, diabetes and fights infections. It also helps an unborn baby grow properly.

How Come Some People Have a Deficiency?

It is believed that between 40% and 60% of the population in this country have a vitamin D deficiency, and this includes pregnant women. There are many reasons for this deficiency, not in the least because there are so few foods that contain sufficient levels. Most of the vitamin D we consume comes from fortified milk, but with an increasing amount of people being lactose intolerant, it is no surprise that the levels of deficiency are on the rise.

In addition, it isn’t just about the food you eat. There may also be reasons why your body is unable to create and absorb enough of the ‘sunshine vitamin’. Some common factors include:

• The season
• Where you live
• Skin pigmentation
• How often you expose you skin to the sun without sunblock
• Levels of pollution
• Your weight
• Your digestive system
• Your age

How to Get Vitamin D

There are two ways to get vitamin D:

1. By exposing your skin directly to sunlight between April and October, between 11am and 3pm. This is in areas that have clearly defined four seasons. The further north you live, the less you will be able to absorb vitamin D through sun exposure.
2. By thinking about what you eat. If you eat plenty of oily fish (sardines, mackerel, salmon) at least twice a week, as well as consume egg yolks, red meat, fortified cereals and fortified milk, you should be able to increase your vitamin D level as well.

The table below shows just how low naturally occurring levels of vitamin D are:

Food Levels of Vitamin D in IU
1 cup of cereal, fortified with vitamin D 40 to 50
Egg yolk 25
8 oz of fortified soy milk 100
8 oz of fortified cow’s milk 98
8 oz of fortified orange juice 100
1 packet of Quaker nutrition for women 154
3 oz of canned in oil tuna 200
3 oz of canned sardines 231
3 oz of mackerel 306
Multivitamins (generic) 400
Infant supplements (generic) 400
Prenatal vitamins (generic) 400
3 oz of catfish 425
3 oz of canned pink salmon 530
1 tablespoon of cod liver oil 1360
3 oz of herring 1383
Over the counter supplements (generic) 2000 (highest level)
Vitamin D prescription for deficiency 50000

Prenatal Vitamins

A recent study looked into prenatal vitamins and it found that women should take around 4,000 IU per day in order to notice the difference during pregnancy. That is around ten times more than most prenatal vitamins.

What About Vegetarians and Vegans?

One thing you may have noticed from the above list is that most products are animal based. This means that if you are a vegan or vegetarian, you may struggle with getting enough vitamin D, especially when you are pregnant. There are many other reasons as to why you may not be able to consume animal products. It is important that a medical professional is aware of this in order to find a solution.

Important Research into Vitamin D and Pregnancy

New research has shown that women who increase their intake of vitamin D when they are pregnant significantly reduce the chances of developing complications, including infections, preterm birth and gestational diabetes. It is after this research that the officially recommended IU of vitamin D became 4,000, a tenfold increase from the previously recommended amount.

During the study, women took 4,000 IU of vitamin D in trimesters two and three and no harm came to them or their unborn. Yet, they suffered twice as few complications than those women who took just 400 IU. The study was completed by the Medical University of South Carolina and was truly life changing for many.

Interestingly, or controversially, there has long been a link between high dosages of vitamin D and birth defects, but this research suggests the opposite is true. According to researchers, there is actually no scientific evidence to suggest vitamin D is toxic, despite popular belief. They suggest that taking as much as 10,000 IU is not toxic.

In the study, some 500 women from Charleston, SC, who were three or four months pregnant were studied. They were divided into three groups, one taking 400 IU, one taking 2,000 IU and one taking 4,000 IU each day until delivery. Those on the highest IU group were least likely to have a vitamin D deficiency at the end of pregnancy (unsurprisingly), and their babies also didn’t have a deficiency. This group also experienced the lowest complication rates. Women in the 400 IU group, by contrast, were twice as likely to develop preeclampsia, high blood pressure and gestational diabetes. They were also more likely to go into early labor.

This research is very significant, because rickets, also known as soft bones, a condition that was virtually eradicated in the modern world, but once again occurring. Furthermore, scientists now know that vitamin D helps fight a range of diseases, as well as support the immune system. None of that is really new, and this is why milk and dairy products are often fortified. However, researchers believe this is by far not enough to make a meaningful difference to pregnant women.

Most people, particularly in Charleston, SC’s sunny climate, feel that they will top levels up through sun exposure. However, researchers found this was untrue. Out of the 500 women who took part in the study, 94% of the African-American subjects had a deficiency at the start of the study, as did 66% of the Hispanic women and, finally, 50% of the Caucasian women.

Do I Have to Take a Supplement?

So what do you do when you are pregnant? First of all, taking a supplement is always recommended. The big question, however, is how much you should take. It is best to discuss this with your physician, because not all sign up to the school of thought that 4,000 IU is what is needed. It is particularly important that you take a supplement if:

• You are Middle Eastern, Caribbean, African or South Asian
• You cover up when you are outside, wear strong sunscreen or otherwise spend a lot of time indoors
• Don’t consume many foods high in levels of vitamin D
• Have a BMI (body mass index) of 30 or higher

If you do decide to supplement, you need to make sure that the product you choose is suitable to be used during pregnancy. Do also check the levels of vitamin D contained in the product and speak to your healthcare professional about whether or not this is sufficient.

It is also very important to continue to supplement if you breastfeed. If you have a vitamin D deficiency, which is likely, you also won’t be able to provide your baby with enough vitamin D until he is weaned and move on to solid foods.

Resources and References:

Vitamin D in Pregnancy – Effects of vitamin D in pregnant women. (Royal College of Obstetricians & Gynaecologists)
Vitamin D and Pregnancy – Relationship between vitamin D and pregnancy. (American Pregnancy Association)
Vitamin D Supplementation in Pregnant Women – Use of vitamin D supplements by pregnant women. (WHO)
Vitamin D During Pregnancy and Breastfeeding – Impact of vitamin D on pregnancy and breastfeeding. (Vitamin D Council)