Parents often question why their breastfed baby needs Vitamin D. Breast milk is the best source of nutrition for your baby. It contains the perfect balance of fats, proteins, carbohydrates and most of the vitamins that are critical for growth and development. That’s exactly it. Breastmilk provides “most, not all” of the vitamins required by a breastfed infant.

If breast milk is the perfect source of nutrition, then why do we need to supplement with Vitamin D?

I like to explain it to my patients in this way: nature provides so many beautiful examples of balance and dependency.

The tides need the moon and gravity to keep our oceans moving, flowers need bees for pollination, the rain needs the sun’s evaporation, healthy bones need calcium, and calcium needs Vitamin D.

Unfortunately, the human impact often disturbs these natural phenomena. Pollution, bad agricultural practices, deforestation and global warming do impact the balances that nature has created. In the same way, our modern lifestyle also impacts the balance within the human body. Pollution, poor diet, and limited time spent outside all have an impact on the amount of Vitamin D our bodies receive. This results in a disturbance of the Vitamin D and calcium balance.

All babies need 400 IU of Vitamin D daily, beginning within the first few days of life. Breastmilk provides about 5 to 80 IU of vitamin D per litre, and this is not enough for strong, healthy bones. Baby formulas are fortified with Vitamin D to ensure that these requirements are met. Our little breastfed babies also need some help to achieve Vitamin D levels. We do this by supplementing with vitamin D drops.

Why is Vitamin D so important?

Our bodies use calcium and phosphorus to build strong bones, muscles and healthy teeth. Unfortunately, only a fraction of the calcium a baby gets from milk can be absorbed by the intestine. Enter vitamin D, and the intestine is able to absorb a far greater amount of calcium, which then builds the bones, teeth and muscles. You see nature’s perfect balance?

Vitamin D also plays a very important role in a baby’s immunity. Babies who do not get enough vitamin D often suffer from upper and lower respiratory infections. 

What are the consequences of a vitamin D deficiency?

• Rickets – this is a softening and weakening of the bones. Children with rickets may have bone deformities, bowed legs, fractures and growth failure.
• Immune issues – Since vitamin D plays an important role in supporting immunity, a child with a deficiency may get recurrent upper or lower respiratory infections.
• Muscle function – Vitamin D deficiency affects calcium absorption. Calcium is essential for our muscles to contract. The heart is just one muscle that relies heavily on its ability to contract, so that it can send blood and oxygen around our bodies.
• Low blood calcium – Vitamin D encourages calcium absorption. Poor vitamin D levels will lead to poor calcium levels in the blood. This, in turn, causes muscle cramps and could lead to seizures.
• Inability to clot – A child with good vitamin D levels and good calcium levels stops bleeding when he or she gets hurt. Calcium plays a very important role in blood clotting.
• Mental health – Vitamin D is not only good for physical health, but also plays a role in mental health. Low vitamin D levels affect anxiety, depression and mood. Recent studies suggest that there is a link between infant vitamin D deficiency and certain mental health conditions like ADHD, schizophrenia and autism. 

What factors increase the risk of Vitamin D deficiency? 

As I explained in the introduction, there are certain things which affect your baby’s vitamin D levels. These include:

1. Limited exposure to sunlight. Sunlight triggers a chemical reaction in the skin, which then produces Vitamin D in a form that the body can use. Another balance of nature! There is, however, a risk of your baby developing a vitamin D deficiency when there is limited exposure to sunlight. Unfortunately, there is a risk to exposing this delicate skin to excessive sunlight, as the skin may burn, and this is ultimately a risk for skin cancer.
2. Darker skin pigment – Babies with a dark skin complexion produce less vitamin D than light-skinned babies when exposed to sunlight. This is because they have more melanin, and this acts as a natural sunscreen.
3. Prematurity – A baby that is born before 37 weeks of gestation has less time in utero to absorb vitamin D from the mother’s bloodstream.
4. Maternal Vitamin D deficiency – Vitamin D deficiency affects about 1 billion people worldwide. Factors like climate, diet, skin colour, pollution and so on impact us all. Mothers are not exempt from this. Babies born to mothers with a vitamin D deficiency are then likely to have a deficiency themselves.
5. Suncream – Suncream does a fabulous job in protecting babies from harmful UV rays. The sunscreen may also block UVB rays, and these are important for vitamin D production in the skin. This definitely does not mean that you should stop using sun cream to protect your little one’s skin. The harm that sunburn does far outweighs the effect of sun cream on vitamin D levels.
6. Air pollution: Every day, I see reports on my weather app of poor air quality. This is not only bad for our babies’ lungs but also bad for their Vitamin D levels. Pollution hangs like a blanket over us and blocks the amount of UVB radiation that reaches us, and interferes with vitamin D synthesis.
7. Other factors – Our clothing, where we live in the world, and the number of opportunities to get outside are all factors which may influence the amount of sunlight we get and thus affect our vitamin D levels. The same goes for our children. 

Conclusion:

Vitamin D deficiency can lead to a host of unnecessary complications. Most of the factors that impact our vitamin D levels are beyond our control. We cannot change the air pollution; we need to protect delicate skin from sunburn, and some of us are born with different complexions. These are just facts of life that influence the balance that nature intended. What we can control is the amount of vitamin D we have in our bloodstreams.

I want to stress that this blog is to draw everyone’s attention to the critical role vitamin D plays in our lives. Adults are not exempt, but babies are growing and developing at such a rate that they cannot afford to go without this incredible vitamin.

Baby formulas are usually fortified with vitamin D, so bottle-fed infants are receiving the required daily amount of vitamin D. Mothers working hard to breastfeed their babies have the opportunity to ensure that their babies receive the correct amount of vitamin D by supplementing. If you are unsure or need to ask more questions about this, please reach out to your healthcare providers.

References:

• https://pubmed.ncbi.nlm.nih.gov/21384086
• https://pmc.ncbi.nlm.nih.gov/articles/PMC10609616/
• https://my.clevelandclinic.org/health/diseases/15050-vitamin-d-vitamin-d-deficiency
• https://www.webmd.com/vitamins-and-supplements/what-to-know-about-vitamin-d-and-mental-health
• https://publications.aap.org/pediatrics/article-abstract/136/4/625/73874/Maternal-Versus-Infant-Vitamin-D-Supplementation