April 11, 2022

What Your Doctor Wants You to Know About Vitamin D

photo of Jordan Shakeshaft

Written By

Jordan Shakeshaft

photo of Kerri Masutto, MD

Medically Reviewed By

Kerri Masutto, MD


photo of Vinita Tandon, MD

Medically Reviewed By

Vinita Tandon, MD

Lifeforce Medical Director

What Your Doctor Wants You to Know About Vitamin D

First things first: Vitamin D isn’t actually a vitamin at all. It’s a hormone. 

That’s right, the so-called sunshine vitamin we’ve been striving (and often failing) to get in sufficient quantities from the sun, is even more crucial to our bodies than many of us had thought. 

“It was only named vitamin D because it was discovered after vitamin A, B, and C,” says Dr. Kerri Masutto, a functional medicine expert and Lifeforce’s VP of Clinical Operations. “There are actually six different metabolites — including two main active ones — of this steroid hormone that we refer to as vitamin D, which is why it has so many dramatic effects across our entire body,” Dr. Masutto says.

You probably know vitamin D’s main job is to help maintain strong bones, but it’s also one of our body’s best multitaskers. “Vitamin D affects everything from our cardiovascular system, to our immune system, to the myelination of our nerve cells,” says Dr. Masutto. In other words: the process that allows electrical impulses to transmit quickly and efficiently along the nerve cells, protecting us against certain diseases, like multiple sclerosis. Vitamin D may also help lower your risk of developing an autoimmune disease, according to a recent study in The BMJ

The Real Reasons We’re Deficient 

Trouble is, most of us are lagging way behind in this essential hormone. It’s estimated that up to 40% of American adults are insufficient, and 6% are full-on deficient in vitamin D. And when you consider the multitude of systems vitamin D impacts, it’s no wonder we’re not operating at our best. (Learn your levels with the Lifeforce Diagnostic here.) 

Add to that the reality that, “As we get older, we don't utilize the vitamin D from the sun as efficiently because our skin gets thinner, so it’s not a reliable way to improve levels,“ says Dr. Vinita Tandon, Lifeforce’s Medical Director and board certified endocrinologist. In fact, you’re only getting an estimated 50% of what your skin once absorbed in your earlier days. “Plus, factors like latitude, wearing sunscreen, seasonality, and time of day all add to the equation,” Dr. Tandon says. 

And while you can find vitamin D in some foods, like fish and egg yolks, it’s impossible to get the daily recommended amount (600 IU for adults ages 19 to 70) through food alone. Unless you want to eat 16 egg yolks a day, which zero doctors would recommend.  

The good news: a high-quality supplement can help. 

A Deeper Dive Into Vitamin D 

If you’re still hung up on the vitamin D misnomer, here’s another way to look at it. “It’s technically not a vitamin because our body can endogenously make it from within,” explains Dr. Masutto. So how do we make it exactly? 

When you’re exposed to sunlight, the sun’s ultraviolet B (UVB) rays hit cholesterol in your skin cells, providing the energy needed for vitamin D synthesis to occur. This inactive form of vitamin D gets stored in your body’s fat cells until it’s needed. Then, through a process called hydroxylation, the liver and kidneys turn those vitamin D stores into the active form you need, calcitriol. (And, in case you’re wondering, food undergoes this same process, too.) 

“Once vitamin D is in its active form, then it can interact with many receptors across just about every cell in the body,” says Dr. Hector Lopez, Lifeforce’s Chief Research & Innovation Advisor and world expert in dietary supplement formulation and safety.

But remember when we said the sun and food sources may not be enough to reach optimal levels? “That’s when a good supplement will be your best bet,” says Dr. Tandon.

Lifeforce Vitamin D and K Nutraceutical

A Faster Way to Level Up

There’s just one catch — and that’s time. If you’re vitamin D deficient and you supplement your diet with 1000 IU every day, it will take between eight and 12 weeks to raise your levels by about 15 points, Dr. Lopez says. 

That’s where Lifeforce’s Vitamin D+K nutraceutical has other supplements beat. Lifeforce D+K is formulated with CELLg8® vitamin D, which has been shown to raise vitamin D levels significantly faster than standard vitamin D supplements, thanks to its liposomal delivery system that enhances bioavailability.

In addition to 2400 IU of vitamin D per serving, Lifeforce Vitamin D+K delivers 300 mcg of vitamin K, which helps direct calcium into the bone and away from other tissues that you don’t want calcified, like blood vessels and kidneys, Dr. Lopez says.

Vitamin K comes in two forms, and Lifeforce Vitamin D+K delivers both. K1 is typically found in leafy green vegetables, while K2 can be found in meat and fermented foods. Lifeforce D+K features the purest, most active, and safest form of K2 called K2VITAL®, which brings additional benefits: It stays active longer in the body to promote healthy blood vessel elasticity and immune health, Dr. Lopez says.

A Better Bet for Your Body 

So before you clear out the eggs section of the grocery store, or start baking under the sun like you’re back on spring break, do yourself a favor and opt for a little help from a research-backed supplement. 

In each capsule of Lifeforce Vitamin D+K, you’ll get bioavailable and bioactive vitamin D, clinically proven to improve bone health, immunity, healthy lung function, and more.” This is different than just making sure you have enough vitamin C, for example,” says Dr. Masutto. “It’s about optimizing an important hormone pathway that should be monitored regularly.” 

Learn more about Lifeforce Vitamin D+K here. 

This article was medically reviewed by: 

  • Kerri Masutto, MD, ABIM Board Certified in Internal Medicine, Institute for Functional Medicine Certified Practitioner 

  • Vinita Tandon, MD, ABIM Board Certified in Endocrinology and Metabolism  

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Vitamin D controls the expression of 200+ genes, touching nearly every cell in our bodies. Yet more than 40% of Americans are deficient in this essential vitamin. The Lifeforce D+K formula, the only one of its kind to feature ampli-D®, is clinically proven to raise vitamin D levels three times faster than regular Vitamin D supplements. Lifeforce D+K delivers the most bioavailable and bioactive form of supplemental vitamin D (calcifediol as ampli-D®) to bolster bone health, immune, and neurological function. The addition of a vitamin K1 + K2 blend ensures that calcium is deposited in the bone, versus the soft tissue, for maximum results.