We recently received a question about the vitamin D3 dose in our Optimum DK Formula. The reader was wondering if the 5,000 IUs of vitamin D was “too much,” especially considering that her doctors have told her not to take more than 2,000 IUs of vitamin D per day and that research from Harvard indicated the upper-level max was 4,000 IUs.

That’s a great question, and I’m sure others may be wondering about that too.

So let me enlighten you.

Deficiency is rampant

Vitamin D is unique in that, rather than acquiring it solely from your foods, your body was designed to produce what it needs when your skin is exposed to the ultraviolet B (UVB) rays in sunlight.

But alas, we have severely interrupted Nature’s perfect plan here, primarily because we have been conditioned to shun the sun and/or slather ourselves in sunscreen due to skin cancer concerns (even though the majority of sunscreens don’t block the cancer-causing UVB rays—only UVA—and most deadly skin cancers occur on areas of the body which NEVER see the sun).

No sun exposure = no vitamin D production.

In addition, people living in the Northern hemisphere are at a disadvantage due to limited sunlight in the winter months and cooler temperatures, times when people aren’t wearing short sleeves and going without jackets.

Also, your body uses cholesterol in its production of vitamin D. But statins (cholesterol-lowering drugs) “work” by blocking your body’s cholesterol-producing pathways to lower your total serum cholesterol level. 

It’s not unreasonable to suspect that this cholesterol reduction may lead to lower cellular levels of the cholesterol needed for normal vitamin D synthesis. Although research is continuing in this area, nonetheless, vitamin D testing and supplementation have been recommended for many people taking statins…so clearly, there’s a connection.

And the takeaway here is that, due to all these factors, many of us are seriously running low—current estimates show that up to 90 percent of Americans have a degree of vitamin D deficiency.

The dose is not one size fits all!

Unlike water soluble vitamins where your body can eliminate excesses, vitamin D is fat soluble, meaning it can accumulate in your tissues.

How much vitamin D accumulates? 

The answer is: It varies.

We ALL differ in terms of our ability to use and absorb nutrients and vitamin D is no exception.

Older individuals and those with darker skin color typically have reduced absorption levels.

In addition, people with certain health issues including poor liver function, osteoporosis, Crohn’s disease, inflammatory bowel disease and other autoimmune conditions are at increased risk of vitamin D deficiency.

So, to make a blanket statement that 2,000 IUs is the optimal dose (and 4,000 IUs is excessive) does not take into consideration all the possible variables.

Also, the recommended daily allowances for nutrients have changed over time and have continued to be updated to encompass a variety of health issues. 

For instance, when the RDA was originally established for vitamin D at 600 IUs, it was based ONLY on its role in bone health and was just barely enough to help prevent rickets.

So that clearly didn’t take into account vitamin D’s role in cardiovascular health, the immune system, blood sugar control, cancer prevention and fighting depression, among other things!

More recent research published in the journal Nutrients suggests that 600 IUs of vitamin D isn’t enough to significantly raise levels in people who are deficient.

In addition, research published in StatPearls found that many adults require between 5,000 and 10,000 IUs of vitamin D3 daily to correct a deficiency and maintain healthy vitamin D levels.

And here’s an interesting tidbit—even Harvard’s recommendations have changed.

The 4,000 IU upper-level limit my reader quoted above goes back to (at least) 2017…and other studies have been conducted since that time.

Plus way back in 2009, Harvard was recommending only 1,000 IUs per day, so clearly research is always evolving and science is never settled.

So, what do I do?

The most reliable way to see where you stand with vitamin D is to have your level tested by your doctor. Also, many pharmacies and health stores offer inexpensive finger-prick tests to evaluate vitamin D status as well.

Current studies suggest that 25-hydroxyvitamin D concentrations of 40 ng/mL (100 nmol/L) or above indicate an optimal vitamin D status.

If you’re found to be deficient, it’s likely that supplementation will be recommended. Additional testing at various points in the future will help you see if you’re at the right supplementation dose.

Note that excessive amounts of vitamin D supplementation (typically over 10,000 IUs daily for an extended period of time), especially when taken by someone who already has optimal vitamin D levels, can lead to vitamin D toxicity, although that is rather rare.

Toxicity is characterized by 25-hydroxyvitamin D blood levels greater than 100 ng/mL (250 nmol/L). 

Common symptoms of vitamin D toxicity include: Nausea and vomiting, stomach issues, confusion, unexplained weight loss, elevated blood calcium levels and kidney stones.

Back to Optimum DK Formula

When I designed Optimum DK Formula, my objective was to help as many people as possible to correct deficiencies and optimize their vitamin D levels.

And based on the most current research and health trends, I opted for a 5,000 IU product.

Could that be too much for someone? That’s possible, but it’s far more likely that people using the product are at a point of deficiency and their bodies can benefit from the support of 5,000 IUs.

In the event that testing shows a (slightly) elevated vitamin D level, there is also the option to take Optimum DK Formula every other day to see if that is more in line with what someone’s body needs.

The bottom line

Nutrients are never one size fits all, and vitamin D is certainly a notable example.

The best way to see if you need to supplement and/or are supplementing appropriately is to have ALL of your nutrient levels tested and address deficiencies as needed.

Also keep in mind that your circumstances may change.

For instance, when I lived in Upstate New York, I took 10,000 IUs of vitamin D3 per day. Syracuse is not known for its sunny days and that dose kept my personal vitamin D level healthy.

Well, I moved to Florida in 2021 and lo and behold, I was able to decrease my dose to 5,000 IUs (because the sun actually shines here regularly LOL) and still maintain optimal vitamin D concentrations.

To your health and optimal nutrient levels,

Sherry Brescia

PS: Some Housekeeping...

Danielle wanted me to let you all know ahead of time, the office will be closed (includes email, phones, messages, and shipping) from August 22nd through August 27th, with normal hours resuming August 28th. Shipping will resume on that day as well, and if you've ever seen Danielle get orders out... you'll know your package will be en route quickly upon her return!

The website will be available to you as always during her time off for any orders to be placed or reading needs.

Super Shield (regular) and Digestizol remain delayed at this time while we await the end of a backorder on some essential materials and ingredients.

All updates will be posted on the website's red announcement banner and within our emails as soon as there is news to share. We again, sincerely, apologize for the delay in production and continue to do our best to get things moving without compromising the integrity of our products.