Do you know your Vitamin D levels? Have you ever gotten them checked? It is estimated that 50% of our country’s adult population has insufficient Vitamin D levels. It’s worth learning about your body’s levels.
Jump to a certain part of this post:
- Why you need to care about your Vitamin D levels
- How to check your Vitamin D status
- How much Vitamin D should you supplement with?
- Ways to increase Vitamin D levels
- Vitamin D for fertility, pregnancy, breastfeeding and infants
Why does Vitamin D matter?
Vitamin D is really a hormone produced by the kidneys. It plays an important role in your body’s use of calcium and also your immune system. Vitamin D is produced when you are exposed to sunlight. It can also be obtained from some food sources.
A recent study of nearly 200 COVID-19 patients at a hospital in Spain found that over 80% were Vitamin D deficient (<20 ng/mL). An excerpt from the report states: Vitamin D-deficient COVID-19 patients had a greater prevalence of hypertension and cardiovascular diseases, raised serum ferritin and troponin levels, as well as a longer length of hospital stay than those with serum 25OHD levels ≥20 ng/mL.
Take note that the study above references patients who were clinically deficient. It does not acknowledge patients whose levels were suboptimal.
Another study in the U.S. reports interesting findings around severity of COVID cases. In the group of patients with severe COVID cases (requiring ICU admission, nearly 97% had Vitamin D deficiency.
Another study found that, in patients with COVID-19, “Low vitamin D levels have been associated with an increase in inflammatory cytokines and a significantly increased risk of pneumonia and viral upper respiratory tract infections.”
Here is one other study that reported similar findings and here is one more.
Need any more data? This study found that “…the habitual use of vitamin D supplements was significantly associated with a 34% lower risk of COVID-19 infection.”
Does this mean that if you have low Vitamin D levels, you are more likely to get COVID-19? Not necessarily, but these studies are suggesting that adequate Vitamin D levels do correlate with less severe cases. The findings in the studies above have found correlations between Vitamin D levels and prevalence and/or severity of cases. That doesn’t mean we can assume that low Vitamin D levels lead to increased chances of contracting the virus. There may be other factors at play that the current studies have not been able to account for. For example, obese and diabetic individuals are more likely to be Vitamin D deficient. These same conditions are also a risk factor for contracting COVID. Is it the Vitamin D levels, the elevated blood sugar or a combination of both and more that lead to increased chances? We don’t have enough answers at this time.
As you can see from the studies above, Vitamin D is important for our immunity and our body’s ability to fight off pathogens. Vitamin D is also necessary for preventing conditions such as osteoporosis. It’s worth getting your Vitamin D levels checked and considering taking a supplement.
How can I check my Vitamin D levels?
You can ask your doctor to test your levels. You can also consider an at-home test from a site like Everlywell, although it will take much longer to get your results.
The Institute of Medicine suggests that a 25(OH)D level >20 ng/mL is sufficient for nearly all persons. However, other research and studies suggest that levels below 30ng/mL are considered deficient, with other more recent studies suggesting that 40ng/mL should be the minimum. If you’re close to 30ng/mL, it may still be advisable to take a low-dose daily supplement. This is especially the case if you’re not getting much sun exposure (in general and during the winter months) or consuming foods with Vitamin D.
How much Vitamin D do I need daily?
The official recommendations are that adults ages 19-70 years old take in 600 IU of Vitamin D daily, and individuals over 70 should take in 800 IU per day.
However, there are plenty of studies that suggest these daily requirements are far too low. Public health and governmental recommendations are always behind the current research because it takes years to revise the guidelines.
We would advise you to work with your doctor to determine the appropriate dosage. We also advise you to do your own research so that you are educated and informed on the topic yourself.
What is the best way to get the necessary amount of Vitamin D?
As always, it is preferable to achieve appropriate levels of Vitamin D through natural methods. However, Vitamin D is one nutrient that is very difficult to achieve optimal levels for naturally, due to our modern way of living. Sunlight is the best natural source of Vitamin D, but clothing, sunscreen, seasonal changes and the latitude in which you live all impact how much exposure you actually get to the sun’s UV-B rays (the ones required for Vitamin D production).
This is also one case where food is not a reliable source for achieving the daily requirement. Unless you are spending ample amounts of time in the sunshine with your skin exposed (without sunscreen) and eating a diet rich with seafood, you would likely benefit by taking a daily supplement. Click here to jump straight to that section.
How much daily sun exposure is recommended?
It is estimated that the average person requires around 20 minutes a day in the sun with at least 40% of their skin exposed to achieve proper daily levels (source). It’s possible that you’re able to achieve that in warm-weather months, depending on where you live. However, if you wear sunscreen during those 20 minutes, this likely reduces effectiveness. If you live in a climate that has cold months, you may not be achieving the proper amount of sunlight exposure. In addition, the darker your skin is, the more exposure is needed to achieve adequate Vitamin D production.
As we’ve mentioned in another post, there are really great health benefits from getting sunlight in your eyes. The ideal time for gleaning these benefits is in the morning, but it’s also helpful to have some outside time throughout your day. Try getting outside for a few 10-minute increments, starting in the morning. You’re essentially knocking out “two birds with one stone” – exposing your eyes to sunlight, helping support your circadian rhythm, and also encouraging Vitamin D production.
This strategy may not be practical in your geography during the winter months (bundling up is a little counterproductive to exposing your skin to the sun!). This may be a time to consider replacing the lost sunlight exposure with more focused nutrition, and/or an additional Vitamin D supplement.
Can I get Vitamin D from food?
Yes, some foods contain Vitamin D. According to the National Institutes of Health, fatty fish are the best sources, as they contain the highest amounts of Vitamin D out of any other food source. For reference, a 3-ounce portion of sockeye salmon contains 570 IU of Vitamin D. Other foods containing Vitamin D include egg yolks (44 IU), beef liver (42 IU), cheddar cheese (12 IU), chicken (4 IU), mushrooms (4 IU) and ground beef (1.7 IU). As you can see, you would need to eat a large amount of these items to achieve your recommended daily intake.
Cow’s milk is also fortified with Vitamin D (approximately 120 IU).
One caveat to obtaining Vitamin D through either food sources and/or supplementation is that sometimes our bodies do not absorb nutrients and minerals the way they should (oftentimes due to other health issues that we may or may not be aware of). That’s why it’s helpful to understand your blood levels in addition to your current sources of Vitamin D. From there you can work with a doctor to determine any supplementation necessary.
How much Vitamin D should I supplement with?
As a reminder, we are not medical professionals. We are passionate researchers and have read enough information from expert resources and medical professionals to share this information confidently. We encourage you to do your own research as well and to work with your medical provider to determine the optimal dosage for your body.
We asked pharmacist Dr. Kealy Marth, PharmD, for her professional recommendation around Vitamin D supplementation. Here is her response:
“For someone looking to supplement their diet with vitamin D, a dose of 600 IU to 2,000 IU taken once daily is likely a safe initial dose for most people, though one should discuss vitamin D supplementation with their provider prior to initiating therapy.”
Multiple studies and experts have made the case for taking a supplement dose of at least 2,000 IU daily.
If you are currently trying to conceive, are pregnant and/or breastfeeding, be sure to read this section about your higher requirements.
What type of supplement is best?
Vitamins and nutrients work synergistically. For this reason, our preference for Vitamin D supplementation is D3K2. Vitamin D3 is more effective at raising Vitamin D levels than Vitamin D2. Vitamin K2 is integral to the body’s appropriate use of Vitamin D and calcium by the body. Think of it this way – Vitamin D3 helps the body absorb the calcium. Vitamin K2 tells the calcium to go to the bones (rather than the heart). You can acquire proper amounts of Vitamin K2 through food, although most people aren’t consuming enough of the foods that contain this nutrient (e.g. natto, sauerkraut, organ meats). The next best supplement option would simply be Vitamin D3.
In addition, Vitamin D is a fat-soluble vitamin, meaning it requires fat sources to be absorbed properly by the body. It’s important to take your supplement alongside a healthy fat source, such as olive oil, raw cheese, avocado, walnuts or fatty fish. Interestingly, Irene’s D3K2 supplement specifically says it is “nanoemulsified” and should be taken on an empty stomach. That’s because it is already in a form that’s bioavailable to the body. In other words, you’ll need to reach the packaging and instructions for your supplement.
Here’s the supplement Irene purchases.
What about supplementation during pregnancy, while breastfeeding and/or for infants?
Pregnancy and Trying to Conceive
Adequate Vitamin D levels are even more critical for promoting fertility and while pregnant and breastfeeding. And yet, pregnant women are some of the most at-risk individuals for deficiency. One of my (Brianna’s) favorite prenatal nutrition experts, Lily Nichols, offers evidence for taking 4,000 IU of Vitamin D daily while pregnant. Several studies suggest this is the MINIMUM threshold for supplementation that supports a pregnant woman’s body in turning the Vitamin D into its active, usable form and having optimal levels (which are higher during pregnancy). I personally took more than this amount daily.
Doesn’t My Prenatal Vitamin Cover My Needs?
Most prenatals contain a small amount of Vitamin D, but likely nowhere close to the 4,000 IU dosage. You will likely need to take an additional Vitamin D supplement, and you would benefit most by taking one that also includes Vitamin K2 (more on that below!).
Breastfeeding and Infant Requirements
When I (Brianna) took my newborn son to his early pediatric appointments, our pediatrician permitted us not to provide my son with a Vitamin D supplement. The reason was because I was already supplementing with enough Vitamin D for Brooks to obtain the necessary amount through my breast milk. We asked Dr. Marth for her opinion on this as well and here is her response:
“Currently the American Academy of Pediatrics only recommends that parents provide vitamin D supplementation to the baby with 400 IU daily.* There are, however, some data that suggests that mothers who breastfeed their child can take vitamin D supplementation and can achieve high enough concentrations in their breastmilk which correlates to therapeutic levels of vitamin D in the baby’s bloodstream. One study in particular found that “maternal vitamin D supplementation with 6400 IU/day safely supplies breast milk with adequate vitamin D to satisfy her nursing infant’s requirement and offers an alternate strategy to direct infant supplementation”.** In my opinion, it seems reasonable to work with your pediatrician to come up with an appropriate maternal vitamin D dose to adequately provide supplementation to your baby.”
Lily Nichols mentions these same studies in her article as well. Therefore, most breastfeeding women would benefit by taking a daily supplement of at least 6,400 IU to ensure she has adequate levels for herself, and to pass on to her baby through her milk.
If you are currently pregnant AND breastfeeding, note that your optimal Vitamin D level will be even higher. Hopefully you can work with your medical provider to identify the proper daily supplement dose. However, some professionals still go by the old supplementation ideas and will recommend a dose that is far too low for what your body actually needs to reach optimal levels.
We hope this article helps provide some useful information about Vitamin D. Our goal is to help others become more educated about their own bodies and their health.
Advocates for your health,
Irene & Brianna
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- *Wagner CL, Greer FR; American Academy of Pediatrics Section on Breastfeeding; American Academy of Pediatrics Committee on Nutrition. Prevention of rickets and vitamin D deficiency in infants, children, and adolescents [published correction appears in Pediatrics. 2009 Jan;123(1):197]. Pediatrics. 2008;122(5):1142-1152. doi:10.1542/peds.2008-1862
- **Hollis BW, Wagner CL, Howard CR, et al. Maternal Versus Infant Vitamin D Supplementation During Lactation: A Randomized Controlled Trial. Pediatrics. 2015;136(4):625-634. Pediatrics. 2019;144(1):e20191063. doi:10.1542/peds.2019-1063).