Valentine’s Day is over, but that doesn’t mean you shouldn’t still be looking out for your loved ones. Especially because it’s February—and that means it’s American Heart Month, a time of year dedicated to the importance of being heart healthy and discovering ways we can do loving things for our hearts.
American Heart Month is a tradition that’s been commemorated for 57 consecutive years and today is heralded by health organizations from the National Institutes of Health (NIH) to the American Heart Association and from traditional news media outlets to bloggers across social and digital media. Here at OmegaQuant, we’re doing our part too.
If you missed last week’s blog, we talked about the importance of being heart healthy and the role for omega-3s EPA and DHA on that journey. This week, we’re going to look at another nutrient that has a beneficial impact on your heart—Vitamin D.
First, a one-question pop quiz. Which of these vitamins is not like the other: Vitamin B, Vitamin C, Vitamin D, Vitamin E?
The answer is Vitamin D. Because Vitamin D is technically a steroid—but not the controversial kind. According to the medical definition of vitamin D, it is described as a steroid vitamin that acts more like a hormone than a vitamin, and it promotes the intestinal absorption and metabolism of calcium and phosphorus.
Vitamin D is also identified as one of the 13 essential vitamins that help to keep the body working properly, according to the NIH. (Vitamin D has that designation in common with Vitamins B, C and E.)
Later on in this blog, we’ll share more background about Vitamin D and talk about the importance of understanding your Vitamin D levels. But first let’s talk about the health benefits of the vitamin known as the “sunshine” vitamin.
Vitamin D: Does it Really Do Everything but Wash Your Car?
When it comes to the benefits of Vitamin D, there’s a lot! You may not be aware that it impacts your immune system, aids in normal development of your teeth, and even helps your skin stay healthy. The reason you may not be aware of those benefits is because Vitamin D is best known for its role in working with calcium to help build, and maintain, strong bones. Vitamin D also supports your muscles to avoid falls, which could result in broken bones. And although in America we don’t talk much anymore about rickets, a condition in mainly children, but also adults, that causes bones to become soft and deformed, Vitamin D deficiency is usually the cause.
Now scientists are talking about the role of vitamin D in heart health: does vitamin D help the heart? One of the things they’re finding is that the lack of Vitamin D may hurt your heart health.
According to information from Dr. Erin Donnelly Michos at Johns Hopkins Women’s Cardiovascular Health Center, a growing number of studies point to vitamin D deficiency as a risk factor for heart attacks, congestive heart failure, peripheral arterial disease (PAD), strokes and the conditions associated with cardiovascular disease, including high blood pressure and diabetes.
Dr. Michos has examined and contributed a great deal of data on vitamin D deficiency and the heart, including a study published in the Archives of Internal Medicine. She stops short, however, of stating that raising vitamin D levels lowers the risk of cardiovascular disease.
“Now that we have identified this risk factor for heart disease,” says Michos, “the question is, if you’re deficient and I give you vitamin D back, can I actually prevent a heart attack?” Michos believes that question will likely be answered more conclusively by large clinical trials as research continues to be conducted.
Is Vitamin D Good for the Heart?
Let’s look at two recent studies into the impact of Vitamin D on heart disease.
The first study published online in February 2020 and is a case-control observational study in which the researchers wanted to investigate the relationship between coronary artery disease (CAD), which is the most common type of heart disease in the U.S., and Vitamin D levels in postmenopausal women. Their findings revealed two compelling results: 1) an association between Vitamin D deficiency and CAD in postmenopausal women; and 2) their data suggest that Vitamin D deficiency is an appropriate diagnostic tool for CAD assessments.
The study population consisted of two groups: 93 menopausal women, ages 50-79 years old, undergoing coronary angiography for evaluation of CAD, and 119 age-matched female controls. The inclusion criteria were postmenopausal women over the age of 50; over 50% angiographic stenosis of at least one coronary artery; and not receiving calcium or Vitamin D. Among the five exclusion criteria were metabolic Vitamin D disorders; renal failure; or malignancies liver associated disease. The study was conducted among patients at a hospital in China from the hospital’s unit, which primarily admits elderly patients with respiratory or cardiovascular disease.
Vitamin D levels were classified into three categories: deficiency was classed as 25(OH)D <10 ng/mL; Vitamin D insufficiency was classed as 10 to <20 ng/mL; and normal (or adequate) Vitamin D levels were considered 25(OH)D ≥ 20 ng/mL.
Of the 212 postmenopausal women, the Vitamin D status broke down as follows: adequate (n = 19), insufficient (n = 66) and deficient (n = 127). The mean age of those groups significantly differed, but all other demographics and laboratory measurements were comparable.
The findings identified the prevalence of CAD in the women based on Vitamin D status as follows: CAD occurred in 5 of the 19 patients (26.3%) in the adequate group; 21 of the 66 (31.8%) in the insufficient group; and 67 of the 127 (52.8%) in the deficient group. Therefore, the authors noted that the prevalence of CAD increased gradually in patients based on their Vitamin D status.
The risk of CAD was 3-fold higher in those with Vitamin D deficiency compared to those with adequate Vitamin D status. According to the researchers, serum 25(OH)D levels are thus clinically relevant to CAD prevalence.
The researchers employed a multivariate logistic regression analysis to determine the association between Vitamin D status and CAD after adjusting for age and risk factors. The multivariate regression analysis further revealed that Vitamin D deficiency increased CAD prevalence as an independent correlate in addition to age, BMI, diabetes, and hypertension, smoking, family history of CAD, and other factors.
In reporting their findings, the authors noted several study limitations, including the fact that the study was observational, not an RCT, and no follow-up studies were performed—meaning no causal relationship could be determined. In addition, the authors noted the small sample size and recommended follow-up studies to verify and build on their results. In that vein, they also suggested that factors such as sunlight exposure and information on inflammatory cytokines be included in order to identify the mechanisms associated with Vitamin D deficiency and seemingly subsequent CAD.
New Meta-Analysis Suggests Some Benefits, Some Null Results
Researchers from two universities in Iran conducted a systematic review and meta-analysis on the effects of Vitamin D supplementation on the clinical outcomes of patients with coronary artery disease (CAD), published online last July.
The authors noted that several studies have illustrated the relationship between Vitamin D deficiency and CAD, with most of the studies finding that vitamin D status was inversely related to CAD. In their meta-analysis they sought to determine that effect based only on results from randomized clinical trials.
After reviewing the relevant body of literature between January 2000 and January 2018, they identified four RCTs (total 299 patients) for their meta-analysis based on the following inclusion criteria: 1) adult patients with CAD and no restrictions on sex, age or race; 2) studies with any form and dose of vitamin D supplements; 3) a Vitamin D group and a placebo group; and 4) outcomes that evaluated the concentrations of hs-CRP for inflammation, blood pressure, lipid profile and parathyroid hormone (PTH).
All four of the included RCTs used a parallel design and an intervention period ranging between 8 weeks to 6 months, had a range of sample size from 60-91 participants above 50 years old, and were published between 2012-2018. More than 50% of the participants were men.
In three of the four RCTs, the oral dose of Vitamin D was 50,000 IU weekly and 0.5 µg daily in the remaining trial.
The pooled results indicated that Vitamin D supplementation in Vitamin D deficient subjects had a favorable impact on diastolic blood pressure levels and parathyroid hormone concentration in comparison to the control population. There was not, however, a significant difference between the Vitamin D and control groups with regard to total cholesterol, triglycerides, LDL, HDL or systolic vs diastolic blood pressure.
Therefore, the authors concluded that Vitamin D may be recommended as an adjunct therapy to routine treatment in CAD patients with Vitamin D deficiency. Further they call on researchers to conduct well-designed clinical trials on a larger scale and duration as a means to determine the actual impact of vitamin D supplementation on clinical outcomes for patients with CAD.
Ways to Improve Your Vitamin D Status
Johns Hopkins’ Dr. Michos reminds us that while a direct link has yet to be formed between higher vitamin D levels and lower cardiovascular risk, it’s important not to overlook other possible benefits.
Vitamin D has long been known as the “sunshine vitamin” because your body produces it when you’re exposed to the sun. In fact, sun exposure is the most natural source of Vitamin D. But these days, the advice from medical professionals is to wear sunscreen when you’re outdoors, and sunscreen blocks the absorption of the sun, limiting the sun’s ability to help us make our own Vitamin D.
Fortunately, there are other ways to easily obtain the Vitamin D you need, from food and dietary supplements. Most of us need that assistance because—and this may be surprising—most Americans fall short of even the average requirements for Vitamin D. Because of that fact, Vitamin D is considered one of five “nutrients of concern” according to the government’s Dietary Guidelines for Americans, the nation’s go-to source for nutrition advice.
There are two main forms of Vitamin D—D3 (cholecalciferol) which is the type that is produced when your body is exposed to sunlight; and D2 (ergocalciferol). Dietary supplements can be purchased in both forms and there are also vegan options. There are also pharmaceutical options that can be prescribed by your doctor, usually in high doses.
Foods considered to be a good source for D3 include fatty fish, such as salmon, tuna and herring; cheese; beef liver; and fortified foods like milk, orange juice and cereal (check the label to see if they’re fortified with Vitamin D); and in smaller amounts, egg yolks and mushrooms. But overall, there are very few foods in nature than contain high amounts of Vitamin D, making dietary supplements an important option to consider if you’re seeking to improve your Vitamin D status.
Why is OmegaQuant Blogging about Vitamin D?
You may be wondering why OmegaQuant is blogging about Vitamin D, when most weeks we blog about omega-3s EPA and DHA.
First, omega-3s and Vitamin D may have more in common than you think. Consider these five facts:
- Both vitamin D and omega-3s play important roles in health as evidenced by the thousands of studies attesting to their benefits for a wide range of health issues, many of which overlap.
- Both Vitamin D and omega-3s are popular among consumers, but still, most of us don’t get enough.
- Some researchers believe that the impact of Vitamin D and Omega-3s could be even more significant when paired together.
- Fatty fish are a good source of both.
- Both Vitamin D and Omega-3 status can be assessed using simple at-home tests (from OmegaQuant).
Read more here.
Second, in case you hadn’t seen our news, OmegaQuant Analytics recently announced we now offer simple, safe, at-home tests to determine your level of Vitamin D.
Here’s why that’s important. This part bears repeating. Most people are just not getting enough Vitamin D.
Research has consistently shown that most people don’t get enough of this important nutrient for a variety of reasons—where they live (e.g., not enough sunny days), what they eat (it’s hard to get enough Vitamin D from food alone), genetics, lifestyle factors, and more.
So, What is The Right Amount of Vitamin D?
There’s not yet a universally agreed upon “optimal” range for Vitamin D. At OmegaQuant, we recommend aiming for a level of at least 30-50 ng/mL. We consider that to be “the goldilocks range” (i.e., not too little, not too much, but just right) where most of the health benefits from having a healthy Vitamin D level have been achieved.
Studies in people with a Vitamin D blood level of 30 ng/mL and above have shown lower risk of overall mortality, lower risk of cardiovascular disease and cancer mortality, lower risk for respiratory tract infections, lower risk of hip fractures and falls, and lower risk of preterm birth.
Figuring out your Vitamin D blood level is simple. Your doctor can draw blood to send to a lab to analyze your results. However, new advances in technology have paved the way for a simpler approach. Now, healthcare providers and patients can access an easy-to-use dried blood spot test that requires a quick finger stick and just a few drops of blood. From those drops of blood, analysis of your Vitamin D blood level can be easily, safely, and accurately measured. And with OmegaQuant’s newly available test, you can do this yourself at-home or ask your doctor to contact OmegaQuant Analytics to use the test at his or her office.
It’s recommended that following the test you discuss your results with your healthcare provider to determine what if any modifications need to be made to your diet, including the possibility of adding (or subtracting) a Vitamin D supplement. Then, monitor your blood levels by re-testing every six months to be sure those modifications have produced the right impact and your target Vitamin D levels are maintained.
The good news is most people can achieve and maintain a desirable Vitamin D level through lifestyle habits like some sun exposure, diet, and supplementation, and regular monitoring.
But don’t get too much of a good thing. Vitamin D blood levels >100ng/mL are above the recommended range and can lead to toxicity symptoms. While Vitamin D supplements can be purchased in doses ranging from 400 IU to 2,000 IU per tablet, some formulations are as high as 10,000 IU per tablet. Be aware that the National Academy of Medicine recommends an upper limit of 4,000 IU of Vitamin D per day. It’s worth having a discussion with your doctor about what dose is right for you.
The bottom line: more and more healthcare practitioners have been encouraging increasing Vitamin D intake alongside testing blood levels to make sure diets (including dietary supplements, if needed) are delivering enough and that intake recommendations are being followed.