Three important reasons to check your vitamin D levels this winter

I’ve written many times about why I recommend you take 10,000 IU of vitamin D3 every day. Vitamin D has been shown to help prevent a whole host of chronic conditions—including Alzheimer’s disease, type II diabetes, depression, and, of course, osteoporosis and other bone-health issues.

Plus, reams of research show that higher levels of D in your blood are beneficial to reduce two major causes of death in the modern world: cancer and heart disease.

But that’s not all. Indeed, the scientific information just keeps coming. And today, I’m sharing with you three new studies on heart disease and cancer that show why NOW is the time to ask your doctor to test your vitamin D levels…

How D affects key risk factors for heart disease

We all know that high blood pressure is a major risk factor for heart disease. Consequently, doctors typically treat hypertension aggressively, prescribing dangerous prescription drugs.

But not enough people (and doctors) know that high blood levels of homocysteine (an amino acid) and C-reactive protein (CRP; a measure of chronic inflammation) are also major risk factors for heart disease.

That’s why two new studies on vitamin D’s impact on these heart-disease markers are so important.

Just 2,000 IU of D a day can substantially lower blood pressure

The first study found significant reductions in blood pressure even with minimal vitamin D supplementation.

Researchers analyzed data from 250 Swiss men and women, ages 60 and older, who took either 800 IU or 2,000 IU of vitamin D daily.1

Results showed that both the 800 IU and 2,000 IU groups had significant reductions in blood pressure. In addition, those taking 2,000 IU (a minimally adequate dose) had a 4 percent decrease of systolic blood pressure (the top number on a blood-pressure reading). This is important because high systolic numbers have been linked to heart, kidney, and vascular diseases.

It’s encouraging that even these marginal amounts of vitamin D show heart and blood pressure benefits. So just imagine the benefits of taking larger doses and attaining higher blood levels of vitamin D!

The natural way to reduce homocysteine and inflammation

The second new study analyzed the effects of vitamin D3 supplementation on homocysteine, CRP, and liver and kidney function tests in overweight women with D deficiency.2

The clinical trial involved 100 women. For two months, 50 women took a placebo and the other 50 received 50,000 IU of vitamin D3 per week. (Weekly rather than daily supplementation is often the preferred regimen for people who are notably deficient in D.)

Each participant’s vitamin D blood level was measured before and after the study period.  The researchers found that the vitamin D group had significant reductions in homocysteine and CRP levels, and improved measures of liver function.

Ironically, doctors often ignore the role of homocysteine and chronic inflammation in heart disease, and misguidedly focus on reducing cholesterol instead. But besides being a mostly meaningless measure for heart health, the body actually needs cholesterol to make vitamin D and other hormonal compounds.

So if you really want to lower your heart disease risk, focus on keeping your vitamin D levels up, rather than lowering your cholesterol.

How D can protect you against cancer—and chemotherapy

As many studies (and cancer patients) confirm, chemotherapy drugs often do more harm than good. Last year, I wrote about a study that found how chemotherapy actually kills 8.4 percent of lung cancer patients within the first 30 days.3 (This is hardly a surprise when you consider that chemotherapy basically poisons your body.)

In addition, chemotherapy has terrible side effects—such as gastrointestinal (GI) mucositis, which is a painful inflammation and ulceration of the digestive tract.

But a new research review found that vitamin D has promising potential to reduce this GI mucostitis.4

Prior studies also show that D deficiency can increase the severity and progression of GI diseases like irritable bowel syndrome and colon cancer. The researchers note that vitamin D has anti-inflammatory and immune-boosting effects in the intestine, and thus might reduce the severity of chemotherapy-related GI mucositis as well.

I’ve reported before on the dramatic benefits of vitamin D for increasing survival and improving quality of life in people with cancer. And this new study suggests that vitamin D also reduces the toxicity of the mainstream cancer treatments that few cancer patients escape—providing yet another reason why cancer patients with higher blood levels of D fare better. 

Ask your doctor for this simple test

It’s easy to determine if you have a vitamin D deficiency. All you need to do is ask your doctor for a blood test called the 25-hydroxy vitamin D, or 25(OH)D test. And now is a good time of year to get one!

Optimal vitamin D blood levels are between 50 and 75 nmol/L. But if you’re one of the millions of people whose levels are lower than that, don’t fret. You can build your levels up by supplementing with 10,000 IU of vitamin D3 a day. (Just remember to get your levels tested once every six months to ensure you’re maintaining optimal levels.)

And supplementing with vitamin D is even more important now, during the fall and winter months. Especially if you live north of Atlanta or Los Angeles.

That’s because, in these parts of the northern hemisphere, from November until March, the sun no longer gets high enough in the sky for the ultraviolet (UV) rays to penetrate through the earth’s atmosphere. (This process creates the photo-activation of D in your skin.)

I like to combine the convenient, highly absorbable liquid form of D3 with the potent marine carotenoid astaxanthin for even more health benefits. Just look for a high-quality supplement from a reputable brand—preferably one with a 100% satisfaction guarantee—and start supplementing today!


1“Effect of daily 2000 IU versus 800 IU vitamin D on blood pressure among adults age 60 years and older: a randomized clinical trial.” Am J Clin Nutr. 2020 Jun 15;nqaa145.

2“Vitamin D3 reduces risk of cardiovascular and liver diseases by lowering homocysteine levels: Double-blinded, randomized, placebo-controlled trial.” Br J Nutr. 2020;1-21.

3“30-day mortality after systemic anticancer treatment for breast and lung cancer in England: a population-based, observational study.” The Lancet, 2016; 13(9) 1203-1216.

4“New therapeutic strategies for combatting gastrointestinal toxicity.” Curr Opin Support Palliat Care. 2020;14(2):142-152.