Why your baby needs a Vitamin D supplement

Vitamin D is a fat-soluble vitamin best known for its important role in how the body uses calcium and phosphor, two minerals crucial for building healthy bones. A severe Vitamin D shortage can lead to a bone-softening disease called rickets, which causes bones to become brittle and to bend more easily. The child may also develop bow legs or knock knees.

Adults can experience a similar condition named osteomalacia, or bone softening.  The fortification of milk with vitamin D in the 1930s was effective in eradicating rickets in the world.

However, although these severe forms of Vitamin D deficiencies are now rarely seen, subclinical Vit D deficiency is still very common. This means having inadequate Vitamin D levels, but without the specific signs and symptoms of bone abnormalities. More recent studies are now linking vitamin D deficiency to cancer, cardiovascular disease, diabetes, autoimmune diseases, and depression.

How common is Vitamin D deficiency?

The statistics on Vitamin D deficiency will depend on the country you live in, and on factors like your skin colour, age, weight, where you live and whether you work/live mostly inside or outside. There are studies on Vitamin D deficiencies in South Africa, but many of them are quite old, or quite small, or only done on a certain population. The truth is that we simply do not know.

Just to give an idea of the magnitude of the problem, one can look at global statistics. It is estimated that up to 50% of people suffer from Vitamin D deficiency worldwide. In the United States, 47% of African American infants and 56% of Caucasian infants have vitamin D deficiency, while over 90% of infants in Iran, Turkey, and India have vitamin D deficiency. We can know for sure that it is a problem for many of our own babies as well

Firstly, where can I get Vitamin D?

You probably know the answer to this question, which is of course through sunlight. When exposed to UV rays in sunshine the human skin can amazingly manufacture its own Vitamin D. Sunlight is the main source of vitamin D for humans, and most people will meet at least some of their vitamin D needs through exposure to sunlight.

There are some limitations though. Firstly, you need to actually get in the sun, which many people don’t do. And to maintain your Vitamin D levels you would need at least 10-30 minutes of no-sunscreen exposure to sunlight over the middle of the day at least twice a week to the face, arms legs or back.

But due to the damage in our ozone layer, UV radiation is far more dangerous now than a few decades ago. Sun exposure is one of the biggest causes of skin cancer, and we no longer advise no-sunscreen sun exposure. Using sunscreen unfortunately block UV rays and reduce Vitamin D production.

The sun is also less effective in winter time. There will be less exposure on a cloudy day and when in partial shade. UV rays do not penetrate glass, so indoor exposure doesn’t help.

Lastly, people with fair skins are better able to manufacture vitamin D than those with a darker skin colour, making deficiencies actually more common amongst black people.

What about vitamin D in food

Very few foods naturally contain vitamin D. The best sources are oil fish (like salmon and mackerel) and fish liver oils; these are not consumed frequently by most people in South Africa. Small amounts of vitamin D can be found in beef liver, eggs and cheese.

Some foods are also fortified with nutrients, to provide in the needs of the majority of the population. Unfortunately this vitamin D is not always well-absorbed into the body.

Why are babies vulnerable?

Because of the risk of sun exposure, the American  Academy of Pediatrics no longer recommend sun exposure without sunscreen for babies and toddlers. This means that the main source of Vitamin D is no longer safe, And Vitamin D in food babies’ food sources are limited. This means that babies are especially vulnerable to a Vitamin D shortage. They are also in a time of rapid growth and development, making a shortage even more harmful than for grownups.

How would you know if your baby has a shortage?

Most children won’t show symptoms of a deficiency, and the effects may only show years later. Some may experience bone and muscle pains. A shortage of vitamin D can lead to a calcium deficiency which can cause convulsions, especially in small babies.

A blood test can be done to test Vitamin D levels in the blood, but it doesn’t show the amount of Vitamin D stored in body tissues. It is also not yet completely known what normal Vitamin D levels should be, as not all people will develop symptoms of a shortage at the same blood level of Vitamin D. This means accurately testing for and diagnosing a Vitamin D shortage is not that easy. The guidelines for when to supplement with Vitamin D have been developed based on what would be the truth for most individuals.

So why are we not routinely supplementing?

As for all other nutrients, a Recommended Daily Allowance (RDA) has been set for Vitamin D by the Food and Nutrition Board. The RDA of a nutrient is the average amount needed in a day that should fulfil the needs of nearly all healthy persons.

In the case of Vitamin D, the RDA has been set for people living in areas with minimal sun exposure. This makes sense as a lot of the research on this topic comes from countries where the sun shines a lot less that in South Africa. For many years it has been taught that supplementation in a country such as ours is unnecessary. Vitamin D deficiency has never been a big focus of healthcare in our country.

But lifestyle changes over the last few decades have changed this. Many people are indoors far more than outdoors. This includes children.  And because of the risk of skin cancer you should not expose yourself (or your baby) to UV rays over the warmest time of the day without wearing sunscreen.

Vitamin D supplements

The American Academy of Pediatrics recommends a daily intake of 400 IU (international units) of vitamin D in babies, starting soon after birth and continuing throughout childhood.

It is true that breastmilk is low in vitamin D, even if mom is taking a vitamin D supplement. For this reason all exclusive and partially breastfed babies should receive supplements. Don’t forget that breastmilk contains loads of other ingredients not included in formula milk, and most of these cannot be replaced with a supplement. Your breast milk remains by far the superior option for your baby.

If a baby is formula fed exclusively and drinks at least 1 litre of formula a day he should reach the 400IU needed as vitamin D is added into most formulas. Supplementation can start a bit later on when he weans onto cow’s milk.

Vitamin D supplements can be found in a liquid form for babies and as chewable tablets for older children. Choose a supplement that contains vitamin D3 or activated vitamin D, otherwise it won’t be effectively absorbed.