As I sit here writing this blog, it’s cloudy out. It’s the dead of winter, and in many cities around Northern Ontario, where I live, it feels like it’s cloudy often. I know personally this affects my mood even if I am somewhat unaware of it – and I do not often recognize that I’m grumpy until we have a gorgeous sunny day. Then BAM – I realize I have missed the sun so much and do everything possible to get outside. 

Many of us associate Vitamin D with sunshine, and that is right! Our body produces vitamin D when our bare skin is exposed to ultraviolet light (UV). But, that is only one of the many ways to get vitamin D. And in fact, in climates where we don’t have a lot of sunlight all year round (like Northern Ontario)- let alone the right strength of the sun to help us make enough vitamin D – we need to supplement with food and or oral supplements to ensure we’re getting enough.

What Does Vitamin D Do?

Vitamin D is responsible for helping our bodies absorb calcium (which is critical for hormonal functioning), helps keep our bones strong, our muscle fibers moving, and our nerves need it to communicate back to our brain. In short – it’s pretty important. 

Vitamin D deficiency has been declared a worldwide public health issue. Approximately 50% of the population has a Vitamin D deficiency. Yikes. 

Risks of Not Having Enough Vitamin D

Depending on our age group or stage in life (think pregnancy), lack of vitamin D can give us different risks. 

In children, it can produce a disease called rickets – which causes bone malformations, weak bones, and other complications, including heart problems, seizures related to low calcium levels, and easily fractured or broken bones. 

In pregnant women, severe vitamin D deficiency can cause congenital (this means from birth) rickets, skeletal deformities and fractures in the baby. It can also potentially cause a risk of preterm birth, and infant growth restriction. 

How can I get Vitamin D?

There are 3 main ways to get Vitamin D. 

• Sunshine
• Food
• Supplements

Sunshine

The challenge with sunshine is that if you live in Canada – you likely don’t get enough from the sun. Factors like the time of year, the time of day, air pollution, cloud cover, and even how dark our skin is (more melanin makes it harder for us to absorb the light and start making our own vitamin D) etc. all impact how much we’re able to make our own vitamin D from sunlight. 

Food

Vitamin D is a rare vitamin – it is usually not found in food. We have fortified foods (fortified means that it wasn’t in the food naturally; it was added) that often have large daily amounts, including:

• Cow’s milk
• Fortified soy and rice beverages
• Fortified orange juice
• Fortified milk-based products like yogurt

Vitamin D can also be found in fatty fish like salmon, sardines, margarine, and egg yolks.

Getting enough vitamin D from food alone can be challenging, and we don’t know if we truly get enough unless we test the levels in our blood. We cannot improve what we do not measure.

Challenges with Supplementing Vitamin D

Oral supplements become our next best option if we cannot get enough vitamin D from the sun, and it’s hard to get in food. One of the disadvantages of this is there have not been very many studies on doses of vitamin D in pregnancy (because who signs up to be a part of a scientific study when they’re pregnant) so the upper limits are usually fairly conservative. 

It’s also important to note, depending on where you live, even in Canada – you may have to pay out of pocket if you want to have your vitamin D levels checked in your blood. I live in Ontario, where we have free healthcare, and our provincial health coverage (OHIP) does not cover vitamin D blood tests. 

How Much Should I or My Baby Take?

Pregnancy

This one is a tricky one. Depending on the source you look at, you’ll see a whole bunch of different doses. Health Canada says 400 IU per day, Dieticians of Canada says 600 – 4000 IU, and the Society of Obstetricians for the United States (AOGC) says 1000-2000 IU is safe. 

As we know, there are unlikely to be lots of studies done on pregnant women to find the ideal safe amount, speaking to your OB, family doctor/NP or midwife or ND about your vitamin D levels (it’s okay to ask them to check them – especially if you never have) and supplementation amounts that are right for you are essential. 

Lactating Women

I have seen some trending posts going around on social media lately about how we can produce enough vitamin D to transfer to our babies in our breast milk if we supplement at high doses. 

This is important because breast milk contains very little vitamin D – even if the mother’s levels are okay. 

When looking at the data on giving lactation women either really high doses of Vitamin D once or taking high amounts over time, there is some evidence that we can probably get mom’s levels high enough to transfer enough into the breast milk for the baby to have adequate vitamin D levels. BUT (and that’s a big but), this is new emerging evidence, and vitamin D levels need time to get that high. Taking a big dose without consultation from a healthcare provider is NOT recommended, and if you take a few supplements for a few weeks, it won’t make your Vitamin D levels high enough.

Vitamin D is still important for lactating mothers for their health.

Breastfed Babies

Now, because we know that a lot of people are deficient in Vitamin D, and we know it’s hard to get without supplements, and very little of it is transferred through breast milk – most health organizations, including the Canadian Pediatric Society, recommend breastfed infants to take 400 IU of Vitamin D daily to meet their needs, and up to 800 IU if you are from a very northern community (or have risk factors as they outline in their article).  Babies who live in northern communities in Canada who are also Indigenous are particularly high risk for vitamin D deficiency when breastfed, and higher doses may be recommended.

This is usually a fairly simple routine with your baby; I recommend choosing an activity to give to your baby that you do daily (like getting up for the day) rather than a time (sometimes babies get up at 5 am and sometimes at 9 am) to help prevent forgetting to give the dose in sleep-deprived new parents. 

During my breastfeeding appointments, we always talk about vitamin D, even when we are combination feeding (breast and formula), in case these babies should still be supplemented. They are not likely getting enough vitamin D from the formula because they are not drinking it exclusively. 

A supplement I find the easiest for parents to use is Baby D Drops (not an affiliate link), which are available at most local pharmacies. 

Formula-Fed Babies

The good news is that if your baby is exclusively formula-fed, infant formulas in Canada are already fortified with all the vitamin D your baby needs. There is no reason to supplement your child in this age category (0-12 months) unless otherwise prescribed by your doctor, nurse practitioner, pediatrician or ND. 

If you want more breastfeeding support, check out my feeding support page. I help new moms with all types of feeding, whether it’s breast, pumping, bottle or formula. 

Other References Not Previously Linked

Canadian Pediatric Society: Preventing symptomatic vitamin D deficiency and rickets among Indigenous infants and children in Canada  (2022). Paediatrics & Child Health, 27, 127 https://doi.org/10.1093/pch/pxac003

National Institute of Health Information (NIH) (2023). Vitamin D Factsheet for Professionals. Accessed on Feb 5, 2024. https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/ 

Heo JS, Ahn YM, Kim AE, Shin SM. Breastfeeding and vitamin D. Clin Exp Pediatr. 2022 Sep;65(9):418-429. doi: 10.3345/cep.2021.00444. Epub 2021 Dec 14. PMID: 34902960