Dr. Katana B. King

05/12/2026

Differences in Vitamin K1 and K2

A few weeks ago I posted about vitamin D and why D3 is the superior form for everyone. Today I want to follow up with vitamin K2, which works hand in hand with vitamin D.

For generations, vitamin K has mainly been linked to blood clotting. This has kept conventional medicine focused on vitamin K1, while largely overlooking vitamin K2.

Vitamin K1 (phylloquinone) comes from plants. It is abundant in green leafy vegetables like kale, spinach, and broccoli. Its main role is helping the liver produce clotting factors.

Vitamin K2 (menaquinones) is very different. It originates from bacterial synthesis. The MK 4 form is found in animal based foods such as grass fed liver, egg yolks, and butter. Longer chain MK 7 comes from fermented foods like natto. These sources have become limited in modern diets that restrict animal fats and fermented foods.

The real importance of K2 lies in calcium metabolism. Vitamin K2 activates proteins that direct calcium into bones and teeth where it belongs. At the same time, it prevents calcium from depositing in the wrong places such as arteries, heart valves, joints, and other soft tissues. This proper calcium directing is one of the most crucial mechanisms in cardiovascular disease prevention. Calcium buildup in the arteries makes them stiff and narrow. This reduces blood flow to the heart, raises blood pressure, and greatly increases the risk of heart attacks and strokes. By keeping calcium out of the arteries and other soft tissues, K2 helps maintain flexible blood vessels and supports long term heart health.

Vitamin D increases the amount of calcium absorbed from food and raises the body’s need for the proteins that manage where that calcium ends up. Without enough K2 to activate those proteins, optimizing vitamin D can raise the risk of unwanted calcium buildup in soft tissues. Adequate K2 may also help lower the risk of kidney stone formation by keeping calcium out of the wrong places.

In my practice, patients targeting vitamin D levels of 75 to 100 ng/mL benefit most when K2 is addressed as well, especially those concerned about bone density or heart health.
For supplementation, the MK 7 form is preferred for its better absorption and longer action. Effective doses typically range from 100 to 180 micrograms per day, taken with a fat containing meal. This pairs well with vitamin D3.

Prioritizing natural animal and fermented sources, along with smart supplementation when needed, supports better long term health.

04/27/2026

Exciting Progress in Diabetes Research: Stem Cells Helping Restore Natural Insulin Production

As a physician managing many patients with diabetes, I am genuinely excited about recent advances in stem cell therapy coming out of China. Researchers have successfully taken a small sample of patient adipose tissue and reprogrammed those cells into insulin-producing pancreatic islet cells.

In early clinical studies, some patients have become completely insulin-independent, with strong blood sugar control lasting many months to over a year after treatment. This approach goes beyond simply replacing insulin from the outside. It involves transplanting these lab-grown cells that function like a healthy pancreas, sensing glucose levels and releasing insulin exactly as needed. Teams in Shanghai, Peking University, and Shenzhen have shared impressive early results, including functional remission in several Type 1 patients and reversal of long-standing Type 2 diabetes.

Several U.S. companies are also moving forward with similar stem cell-derived islet therapies in advanced clinical trials, with the goal of potential approvals in the coming years.

These remain early-phase studies with relatively small numbers of patients, so larger trials are still needed to confirm long-term safety and effectiveness. For Type 1 diabetes in particular, addressing the autoimmune response continues to be an important challenge.

With over 590 million people living with diabetes worldwide, and over 40 million in the United States alone, this research brings real hope for a future where we can move beyond daily insulin injections toward true biological restoration.

04/23/2026

Differences in Vitamin D

For over 100 years, vitamin D2 has remained the default high-dose prescription form used by most physicians, rooted in early 20th-century recommendations and synthetic production methods. It's time to change.

Vitamin D2, also known as ergocalciferol, is found exclusively in plants and fungi in nature, and is the form commonly added to processed and fortified foods such as milk and cereals. Meaningful amounts are difficult to obtain from unprocessed food sources. The primary natural dietary sources are UV-exposed mushrooms or yeast, but even these provide limited quantities.

In the early 1920s, studies on children with rickets showed that daily cod liver oil resolved the condition. When synthetic D2 became available, direct comparisons showed cod liver oil (natural D3) was superior per unit dose to the synthetic version. Yet, pharmaceutical companies promoted high-dose synthetic D2, stopping at 50,000 IU weekly, because patients could not tolerate higher amounts. Even though cod liver oil reliably resolved rickets in the children, physicians switched to the synthetic form, and they still continue prescribing it to everyone to this day.

Vitamin D3, also known as cholecalciferol, is the form your skin produces when exposed to sunlight. However, most people do not realize that the main sources are animal-based foods, including egg yolks, butter, fatty fish, liver, and other nutrient-dense foods that we have been advised to avoid or limit for the past seventy-five years. These are the traditional foods that historically provided meaningful amounts of vitamin D in the diet. In regions like the Pacific Northwest, meaningful cutaneous synthesis of vitamin D3 from sunlight only occurs during a narrow window, typically July through September, and even then, primarily between 11 a.m. and 1 p.m.

Research consistently demonstrates that D3 is superior to D2 for raising and maintaining healthy blood levels of 25-hydroxyvitamin D. Vitamin D3 is more potent, binds more effectively to vitamin D-binding proteins in the blood, has a longer half-life, and produces greater and more sustained increases in serum levels compared with equivalent doses of D2. These differences mean that D3 more efficiently supports the body's ability to achieve and sustain optimal vitamin D status over time.

Most people recognize that vitamin D supports bone health, yet its influence extends far beyond the skeletal system. Vitamin D receptors are present in nearly every cell in the body, including those in the heart, immune system, brain, and muscles. Optimal vitamin D status contributes to cardiovascular health by helping regulate blood pressure, reduce inflammation, and support cardiac function. It promotes metabolic balance through improved insulin sensitivity and blood sugar regulation. It modulates immune function by supporting both innate and adaptive immunity while potentially lowering autoimmune risk. It influences cellular health by affecting cell growth, differentiation, and protection against certain chronic conditions. It is also linked to mood, energy levels, and overall neurological well-being.

Low vitamin D levels are associated with increased risk across multiple body systems, which is why proper optimization is essential. I target a total vitamin D level of 75 to 100 ng/mL in my patients, as this range appears to offer broader benefits while remaining within safe limits.

The form of vitamin D one obtains matters significantly. D3, derived from natural animal food sources or appropriate supplementation, represents the more effective choice for most individuals. Outdated prescribing patterns should not override current understanding of physiology.

04/20/2026

Grass-Fed Beef from Biodiverse Pastures Delivers Superior Nutrient Density

New 2025 research provides even stronger scientific backing for choosing grass-fed beef. These studies quantify how regenerative grazing practices that promote plant diversity in pastures lead to measurably higher nutrient levels in the beef while supporting healthier ecosystems.

The first study, titled “Soil and Pasture Health Underlie Improved Beef Nutrient Density Determined by Untargeted Metabolomics in Southern US Grass-Finished Beef Systems,” was published in July 2025 in the journal npj Science of Food.

Researchers analyzed soil, forage, and beef samples from regenerative grass-finished operations and paired conventional grain-fed systems. Key findings include:• Pasture soils showed substantially higher levels of organic matter and key minerals compared to soils used for grain production.
• The diverse forage in these pastures contained far higher levels of beneficial plant compounds.
• The grass-fed beef exhibited significantly higher levels of powerful antioxidants, vitamin A, vitamin E, and other protective compounds.
• Conventional grain-fed beef showed higher levels of certain inflammatory markers and compounds associated with reduced metabolic health.

A complementary project released early findings in April 2025: the Beef Nutrient Density Project, a collaboration involving the Bionutrient Institute, Utah State University, and Edacious.

Analysis of more than 300 beef samples across North America demonstrated that beef from ecologically rich, polyculture pastures (with a wide variety of grasses, forbs, and legumes) was notably superior in several health-promoting compounds compared with grain-fed or monoculture systems.

Specific increases included:
• Over 210 percent more alpha-linolenic acid (ALA, an important omega-3 fatty acid)
• Over 117 percent more eicosapentaenoic acid (EPA, another beneficial omega-3)
• Over 103 percent more total omega-3 fatty acids
• Nearly 79 percent more calcium
• Substantially higher levels of plant-derived compounds with antioxidant and anti-inflammatory properties

These results highlight an important environmental point. Rotational grazing on diverse pastures actively promotes plant biodiversity. This increased diversity improves soil health and ecosystem function, which in turn elevates the nutritional quality of the beef through the soil-plant-animal chain.

When selecting beef, I recommend choosing grass-fed/grass-finished products from regenerative farms that emphasize diverse pastures and soil health. This approach supports better nutrient intake, and aligns with principles of food quality that benefit long-term wellness.

04/05/2026

Creatine Hype vs Reality: Why Most People Do Not Need It

Creatine is getting pushed everywhere right now as a must have for muscle, strength, aging, and even brain health. Let us look at what the actual evidence shows.

The strongest proof for improvements in strength, power, and muscle comes from research on elite athletes or in extreme weightlifting. That does not apply to most of us.

For everyday healthy adults, even if you work out a few times a week, the real benefits are slight and highly variable. Around 30 percent of people are non responders, and get little to no benefit at all, because their muscles cannot take up the extra creatine.

Here are the main problems with the studies that get quoted for everyday people:

Older adults and muscle or strength:�Meta analyses pool small trials with only a few hundred participants total. Many have high dropout rates, unclear randomization, no intention to treat analysis, and many differences in dosing, training programs, and duration. The modest extra lean mass of about 2-3 pounds and strength gains are almost always tied to resistance training, not creatine alone. Evidence quality gets downgraded for bias and imprecision. Not impressive for the typical older adult living a normal life.

Vegetarians or vegans:�They start with much lower creatine stores because they do not eat animal products. Of course supplementation helps them more. This is comparing apples to oranges. You cannot generalize those responses to meat eaters who already have normal baseline levels.

This area is the weakest. The reviews only include a small number of tiny studies with just a few hundred people in total. Studies are all over the board with different tests, doses, populations, and durations. Any small improvements that show up are usually seen only in very specific situations and not in typical healthy adults. The idea that creatine is a daily brain booster for everyone is completely overblown.

Bottom line: Creatine is safe and works well for serious athletes and rigorous training. But for the average person with a normal animal protein containing diet and moderate activity, the real world benefit is minimal at best. It is not the daily must have that social media makes it sound like.

01/30/2026

Good article!

Pasture-raised doesn’t mean corn- and soy-free. What this moment really exposes about feed, fatty acids, and the modern egg system.

09/08/2025

Yes!
https://www.instagram.com/reel/DOOHnI0AGbx/?utm_source=ig_web_copy_link

08/14/2025

Lately, I've had a lot of patients coming in asking about beef organ supplements—these are the dried, ground-up, powdered forms of beef organs like liver, heart, kidney, spleen, even ovaries and fallopian tubes, that are marketed as "superfoods" in capsule or powdered form. The claims sound impressive: they will supposedly boost your energy, support your immune system, improve digestion, enhance brain health, regulate hormonal imbalances, and fill nutrient gaps with high doses of vitamins (like vitamin A, B12), minerals (iron, zinc), and other compounds. These supplements, in my opinion, are a waste of money, and the hype is not backed by solid evidence.

First off, while fresh or cooked organ meats are nutrient-dense (think vitamin-rich liver), there is little to no scientific proof that drying, grinding, and capsuling them preserves those benefits or makes them effectively absorbable in the body. Processing can degrade nutrients and bioavailability (how well your body uses them). Most claims rely on anecdotal stories or studies about eating actual organ meat, not the powdered versions.

In fact, there are no high-quality human studies evaluating the efficacy. They can even contain contaminants like heavy metals. If you're deficient in something specific (like iron or B12), a targeted, evidence-based supplement or dietary changes is far better—and cheaper—than these pricey organ blends (which can run $30–$50 a bottle).

Let’s breakdown some of the contents of these supplements. Take iron, for example. One popular beef liver supplement claims to be a rich source of iron, but let’s do the math. Six capsules contain 1000 mg (1 gram) of dried beef liver, which provides just 0.26 mg of iron (based on dried beef liver containing ~26 mg iron per 100 grams).You would need to swallow hundreds of capsules to get anywhere close to meaningful iron intake! I prescribe iron in 30+ mg capsules, and multiple capsules daily for iron deficiency.

Vitamin A is another overhyped claim. Cooked beef liver is indeed high in vitamin A (31,714 IU per 100 grams/approximately 3.5 ounces), but the drying and processing into powders or capsules can degrade this nutrient. Even if some vitamin A remains, you would need massive doses of the supplement to match what you would get from eggs, butter, dairy, etc. Just one tablespoon of cod liver oil contains approximately 13,000 IU’s. Not beta-carotene, actual vitamin A(that’s another subject).

What about B12 content? No precise data exists for B12 loss in dried beef liver, but some loss of heat-sensitive vitamins like B12 can occur. Assuming minimal degradation for an estimate,1000mg of dried beef liver contains approximately 0.71 mcg of B12, with a potential range up to ~2.8 mcg if concentrated without significant loss. For comparison, a typical supplement that I recommend contains 1000mcg of methylcobalamin(B12).

And, claims about minuscule amounts of dried cow/bovine o***y and fallopian tubes having any effect on regulating female hormonal imbalances is just absurd, but I will not expand on that subject in this post!

Bottom line: Don't fall for the marketing. If you are considering these or any other supplements, chat with me first—I can test for deficiencies and recommend what is actually proven to work. Your wallet (and health) will thank you!

05/16/2025

Nutritional Deficiencies: A Hidden Cause of Anxiety and Depression

As a physician, I see many patients that struggle with anxiety and depression, often unaware that low levels of key nutrients like iron, B12, folate, and vitamin D could be contributing to their symptoms, or actually be the underlying cause. These nutrients are vital for brain health, and deficiencies can disrupt mood, energy, and focus. Here’s why they matter:

Iron: Ferritin, a protein that stores and releases iron, fuels oxygen delivery and many mood regulating chemicals like dopamine. Low ferritin levels, common in women from menstruation or pregnancy, men with poor diets, and chronic disease, can cause anxiety, depression, fatigue, and brain fog. I routinely test ferritin to catch this.

B12 powers multiple brain and body functions: it supports serotonin production for mood stability, maintains nerve health to prevent irritability, aids energy metabolism to combat fatigue, and regulates homocysteine, a compound linked to depression when elevated. It also supports DNA synthesis and red blood cell production, ensuring oxygen reaches the brain. Shortages, seen in both genders from vegan diets, aging, or absorption issues, can trigger depression, anxiety, and cognitive fog.

Folate is crucial for brain function: it helps produce mood-stabilizing neurotransmitters like serotonin and dopamine, supports methylation for gene regulation, and lowers homocysteine levels, which can alter emotional health when high. It also aids neural repair and cell growth, protecting against depressed mood and fatigue. Low levels, common in women on contraceptives or during pregnancy and in men under stress or with poor diets, worsen depression and anxiety.

Vitamin D is a brain health powerhouse: it regulates inflammation to stabilize mood, protects neurons to support cognitive clarity, balances neurotransmitters like serotonin for emotional resilience, and modulates the immune system to reduce mood-disrupting inflammation. Deficiencies, widespread in both men and women due to limited sun exposure, darker skin, or low dietary intake, are linked to depression, anxiety, and seasonal well-being.

Outdated lab standards often call levels “normal” when they are too low for optimal mental health, leading to misdiagnoses of psychological issues, when correcting nutrient deficiencies could assist in recovery.

In my practice, correcting these deficiencies can transform lives—something oversimplified mental health approaches miss.



Sources: Journal of Affective Disorders (2015), Nutrients (2017),Frontiers in Neuroscience (2017),Nutrients (2018), American Journal of Clinical Nutrition (2019), Brain and Behavior (2019), Journal of Clinical Endocrinology & Metabolism (2020), Journal of Psychiatric Research (2020), Frontiers in Psychiatry (2021), Nutrients (2022).

05/02/2025

AVOCADO OIL: Buyer Beware

Do you use avocado oil for its advertised health benefits? I am often told by patients that it is the main oil they cook with. I never use it.
Two UC Davis studies (2020 & 2023) tested dozens of avocado oil brands and found some shocking truths:
Quality: Over 82% of oils were oxidized and rancid before their expiration dates.
Purity: Up to 69% were mixed with inexpensive oils like soybean or sunflower. Some “extra virgin” bottles were actually 100% soybean oil!
Smoke Point: Claims of the high smoke point of avocado oil do not hold up under the conditions found in this study, and certainly not if you are purchasing extra virgin oil, which has a smoke point similar to olive oil.

Avocado farming is not environmentally friendly, either. It takes an estimated 70 gallons of water per pound to grow in places like Mexico and California. Deforestation is rampant. In Mexico alone, illegal avocado orchards have cleared thousands of acres of forest, threatening biodiversity and causing heavy pollution. Heavy pesticide use and long-haul shipping (most U.S. avocados come from abroad) make the impact of their consumption even worse.

So, next time you buy avocado oil—or any avocados for that matter—think twice. And, maybe ease up on the avocado toast, too.

Author links open overlay panelHilary S. Green a, et al. “First Report on Quality and Purity Evaluations of Avocado Oil Sold in the US.” Food Control, Elsevier, 3 May 2020, www.sciencedirect.com/science/article/pii/S0956713520302449.
Garcia, Paola. “Avocado Growing Destroying Mexican Forests.” The Food Institute, 21 Dec. 2023, foodinstitute.com/focus/avocado-growing-destroying-mexican-forests/.
Quinton, Amy M. “Study Finds 82 Percent of Avocado Oil Rancid or Mixed with Other Oils.” UC Davis, 11 Oct. 2022, www.ucdavis.edu/food/news/study-finds-82-percent-avocado-oil-rancid-or-mixed-other-oils?utm_source=chatgpt.com.

03/19/2025

The dietary guidelines for Americans have a protein problem.

In her inaugural address at the US Department of Agriculture, Secretary Brooke Rollins affirmed her commitment to "Make America Healthy Again."

Achieving that goal requires revising the Dietary Guidelines for Americans -- the federal government's highly influential nutrition recommendations.

These guidelines shape everything from school lunches to nursing home meals but have long failed to reflect the latest science on an essential nutrient: protein.

For decades, this policy has eroded both the quality and quantity of recommended protein, leaving people of all ages vulnerable to muscle loss and poor health. This shortfall is particularly concerning in schools, where millions of growing children rely on federally funded meals.

The new administration must align the guidelines with science -- and upgrade Americans' protein intake.

Composed of essential amino acids that build and repair muscles, skin, and organs, proteins are foundational for childhood growth, brain development, and immune function.

Yet many children and adolescents aren't getting enough.

According to National Health and Nutrition Examination Survey data, among U.S. children aged 9-14 years, approximately 15% did not even meet the Estimated Average Requirement (EAR) -- a limited benchmark accounting for the needs of only half of healthy individuals in this age group.

For those aged 15-19 years, about 30% fell below the EAR.

This deficit puts children at risk of delayed growth, poor concentration, slow healing, fatigue, and greater susceptibility to flus and viruses.

Protein is also essential at the other end of the age spectrum.

As we get older, our muscles become less responsive to protein intake -- a condition known as anabolic resistance -- making it harder to build muscle mass, fight illness and support good health.

Yet, inexplicably, current guidelines for older adults mirror those for younger adults.

Without adequate protein, older adults are more susceptible to osteoporosis, falls, long hospitalizations, and early death.

Simply put, Americans young and old are not meeting their protein goals. And our nutrition guidelines, with a new version due out this year, should be reformed to help.

My new op-ed in the Wall Street Journal Opinion is out now: https://www.wsj.com/opinion/meat-will-make-america-healthy-again-federal-guidelines-nutrition-reform-protein-eded2b3e