Vitamin D levels: What is optimal and how much do you need?

Here in the Midwest, we find that most people are deficient in vitamin D unless they are taking a quality supplement. Since there are very few foods that naturally contain vitamin D, and most of our vitamin D comes from the sun, it isn’t surprising that we see an uptick of vitamin D related concerns in the cooler/darker months between October and May.  In this article, we will review common symptoms of vitamin D deficiency and give you our take on optimal levels & how much vitamin D most people really need.

Vitamin D is a fat-soluble vitamin that also acts as a hormone. Vitamin D obtained from supplements, food, or sun exposure must be converted via a process called hydroxylation in both the liver and kidneys to become the physiologically active form of vitamin D, 1,25-dihydroxyvitamin D [1,25(OH)2D],also called Calcitriol. 

Some key functions of vitamin D include promoting calcium absorption in the gut, supporting adequate phosphorus concentration, bone growth and remodeling, reducing inflammation, modulating cell growth, and supporting healthy glucose metabolism, among others. 

When we stop and think about how vital this one vitamin is to proper body functioning and prevention of disease, it certainly makes sense to screen for deficiency.

When screening with blood testing, the range of what is considered a normal vitamin D level can vary greatly even among health professionals. At Root, we think the better question is: what is an optimal vitamin D level? Optimal levels of vitamin D should be personalized. Are you experiencing any of the symptoms above? Have you been diagnosed with an autoimmune disease?  Are you currently experiencing inflammation or infection?  Do you have a documented low level of vitamin D?   Your vitamin D optimal level may be different from your neighbor.

Additionally, your vitamin D requirement is unique.  Do you absorb vitamins well? For example, do you have a  healthy gut and intact gallbladder helpful in absorbing fats and vitamins?  Vitamin D is a fat soluble vitamin meaning that vitamin D from food sources gets absorbed along with fats in the intestine. Do you have a difference in your genetics that interferes with the way vitamin D is transported or metabolized?  

These are all things the doctors and dietitians at Root keep in mind when screening and assessing for vitamin D deficiency.  

Are you magnesium deficient? Enzymes that synthesize and metabolize vitamin D are magnesium dependent (1,2).  More than 50% of US adults do not meet their recommended dietary allowance of magnesium.  Because optimizing magnesium levels is important for optimizing vitamin D status, we include both vitamin D and magnesium in our Foundational Supplement Bundle. 

It is also important to take vitamin D alongside vitamin K2 (menaquinone-7).  Taking these together helps reduce arterial calcium deposits and directs vitamin D and calcium into the bones where they belong (3,4). 

If you have been supplementing with vitamin D for quite some time without seeing improvements in your blood levels, consider if adding in vitamin K2 and Magnesium may better support your body in increasing your levels of vitamin D. 

While we can’t give a blanket statement for the optimal vitamin D level, putting all the best evidence together, At Root we believe that vitamin D levels are likely optimal for most people between 50-70 ng/ml. 

We realize this is a stark contrast to what most people are told: that their levels are “normal” over 25-30ng/ml. This is because we personalize and optimize not only your current state of health, but your overall wellness and prevention.

It is ideal to know your blood levels to determine dosing.  

In the warmer months, we encourage everyone to get daily sunlight exposure for at least 15-20 minutes between the hours of 10 a.m.-2 p.m. in addition to likely taking a lower dose of vitamin D3/K2 of around 2,000IU.  This is a generally safe recommendation.  Remember, since vitamin D is fat soluble, it is stored in the body rather than excreted in urine like water-soluble vitamins.  Too much vitamin D can lead to a condition called hypercalcemia.  This is one reason we find testing to be so valuable. 

In the cooler, darker months, it is generally safe to take around 3,000IU per day if you don’t know your blood levels.  If you have documented low levels of vitamin D (less than 30 ng/dl) it is probably best to take 5,000IU or more per day.  It is always best to check with your healthcare provider before starting higher doses of vitamin D. 

Vitamin D deficiency can lead to many problems within the body and often contributes to symptoms like fatigue, mood disturbances, poor immune function, bone and joint issues, and more.   At Root, we believe that ideal levels are between 50-70ng/dl.  The supplement dose you should take really depends on what your blood levels are, but it is generally safe to take 2000-3000IU per day without knowing your levels.  This low-key approach can still make a significant difference in the way you feel. We regularly test for vitamin D levels in our functional medicine membership.