Another news report was released last night referencing the link between vitamin D and an improved response to COVID-19, and perhaps overtime we will see more and more studies supporting this claim which is great. Regardless of when or whether we get further evidence that vitamin D can directly improve our odds against COVID-19, we should all be ensuring that we have adequate levels for many reasons.
Vitamin D regulates immune function
Vitamin D improves many aspects of our immune system. It allows us to better fight viruses, bacteria and other pathogens, while also reducing our likelihood of developing autoimmune conditions like multiple sclerosis.
Vitamin D improves hormonal health
Vitamin D is important for estrogen production in both sexes.
For men, vitamin D deficiencies are linked to lower testosterone levels. For women, vitamin D actually has progesterone-like activity.
Vitamin D appears to play a hormone modulating role which lowers the risk of breast cancer.
Vitamin D improves brain health
Cognitive decline and dementia are associated with low vitamin D status.
Vitamin D is important for bone health and teeth too!
It regulates the absorption of calcium and phosphorus, and is integral to bone health and preventing osteoporosis.
Vitamin D improves cardiovascular health
People with low vitamin D levels have a greater risk of heart attack, heart failure, stroke, diabetes or high blood pressure later in life.
Vitamin D reduces rates diabetes
Vitamin D supplementation improves blood sugar controls in people with type 1 diabetes, type 2 diabetes and healthy individuals.
Low vitamin D levels are associated with insulin resistance and obesity.
Vitamin D improves mood
Vitamin D can help prevent and treat depression in those with inadequate levels.
The importance of adequate vitamin D levels in pregnancy
In pregnancy low vitamin D levels are associated with preeclampsia, gestational diabetes and poor pregnancy outcome. And if mom has adequate vitamin D levels, she can pass an appropriate amount of vitamin D to her newborn and infant via her breast milk, therefore avoiding having to give the baby oral vitamin D directly.
Over my 10 years of practice I have tested hundreds and hundreds of patients’ vitamin D status. I’m not testing to determine IF they’re deficient, I’m testing to see HOW deficient they are. Over 90% of the patients that I’ve tested have been below the widely accepted “normal range”.
What is the normal range for vitamin D?
In Ontario the lab reference range for [25-hydroxy-] vitamin D is:
Deficient < 25 nmol/L
Insufficiency 25-75 nmol/L
Sufficiency 76-250 nmol/L
Toxicity > 250nmol/L
As you can see, in high doses vitamin D can be toxic as it’s a fat soluble vitamin. Only once have I seen anyone even close to this range, and it was likely due to rapid fat/weight loss on a ketogenic diet (once the weight loss plateaued, the vitamin D level returned to normal range).
We synthesize vitamin D in our skin upon exposure to sunlight, however most of us clearly are not getting enough sun exposure in Canada to bring us up to where we need to be.
Where to get your vitamin D
There are very few natural food sources of vitamin D. Salmon, sardines, egg yolk, mushrooms, shrimp to name a few, but other foods contain vitamin D because they have been fortified with them (milk, cereal, orange juice). So often it’s required to take a vitamin D supplement in the winter months at least. But how much do you take?
Health Canada recommends only 600IU per day for adults, which in my clinical experience is extremely low. Perhaps it is this low because they are expecting people to also be eating the fortified foods. However, many of my patients are avoiding dairy and grains due to intolerances, so they require a higher dose.
My preference is not to guess, and to test first to determine what their levels are. Then based on these test results I can determine what dose they likely need, but because we all absorb and utilize nutrients differently, I then re-test their blood vitamin D levels at the following seasonal cut-off (like at the end of winter when levels would naturally be lowest, or at the end of the summer when they will be highest), and based on those levels we determine what the patient’s long-term dosing should be.
Want to know your vitamin D status? Let me know! As my patient I can easily send you to the lab (Dynacare or Lifelabs) to test your vitamin D levels (cost is approximately $50 with a two day turnaround time).