Best Vitamin D3 and K2 Benefits 2022

In recent weeks and months, several publications and studies have suggested that maintaining adequate levels of vitamin D would seem potentially beneficial in fighting the COVID-19 infection. 

 

How do you know that your vitamin D level is adequate? Most people in the United States consume less than recommended amounts of vitamin D. 

 

An analysis of data from the 2015–2016 National Health and Nutrition Examination Survey (NHANES) found that average daily vitamin D intakes from foods and beverages were 5.1 mcg (204 IU) in men, 4.2 mcg (168 IU) in women, and 4.9 mcg (196 IU) in children aged 2–19 years (NHANES).

best vitamin D3 supplement

Is It Better to Take D3 With K2?

Yes, this is because Vitamin D3 and K2 have a synergistic relationship. Taking Vitamin D3 with Vitamin K2 helps to ensure the calcium transported by the Vitamin D is absorbed by your bones where it’s needed, rather than accumulating in your arteries.
 

What Are The Benefits Of Vitamin D3 and K2?

groundbreaking 2017 review compiled over 80 studies that show vitamin D3 and K2 together might be greater than the sum of their parts, when it comes to bone health.

This is likely because vitamin D gets the calcium into the blood, then vitamin K tells the calcium where it is most needed.

Taking vitamin D3 and K2 together actually promotes new bone growth. In 2019, researchers observed that vitamin D3 and K2 worked in tandem to form new osteoblasts, the cells that secrete osteocalcin, which is a biomarker for new bone growth.
 

Best Vitamin D3 and K2 Supplement Brands in 2021

We have done our research and shortlisted the best for you. The list is based on recommendations by third party organizations, online reviews and popularity on search results and forums.

Here are the best vitamin D3 and K2 supplements that you can buy today.

1. SR Plant-Based D3 + K2 with Coconut Oil

– Vitamin D3 + K2 with Organic Virgin Coconut Oil 
– Plant-Based Vegan D3 (5000iu) with MK7 Vitamin K2 (100mcg) from Chickpea 
– Non-GMO & Vegan Certified 
– 60 Veggie Softgels
– 100% Plant based 
– Vegan Certified & Non-Gmo Verified. 
– Soy, Gluten, Gelatin & Carrageenan free
– Formulated with Organic Coconut Oil 
– Manufactured in a cGMP Facility in the USA.
– Made with Vitashine D3 – a patent, plant based form of Vitamin D3 from Lichen and MenaQ7 – a patent form of MK7 from Chickpea
 
Dosage
Vitamin D3 – 125mcg (1 Softgel)
Vitamin K2 – 100mcg (1 Softgel)
 
Ratings
4.8 out of 5 – 22,293 global ratings
 
Reviews
My hair was shedding quite a bit, and my dermatologist tested me for a Vitamin D deficiency (I hardly get any sunlight). Turns out it was pretty severe. This completely stopped and reversed the shedding (thickened my hair) and overall my mood was improved.

2. Bronson Vitamin D3 Plus K2

Amazon Best Sellers Rank: #10 in Vitamin D Supplements.
 
The Perfect Pair: 
Vitamins K2 & D3 were simply meant to be together. Most people know the benefits of Vitamin D, but many don’t realize that Vitamin D NEEDS Vitamin K2 to maximize it’s benefits.
Strong Bones & Healthy Heart: 
This formula not only promotes the proper absorption of calcium with D3, but the correct distribution to your bones where you need it most.
Superior Quality Vegetarian Capsules: 
Laboratory tested, NON-GMO, GLUTEN FREE, & SOY FREE. All Bronson products are tested in our state-of-the-art facility in New York.
Trusted Since 1960: 
The pioneers of Bronson Vitamins were a group of pharmacists who witnessed the benefits of vitamins and mineral supplementation firsthand with their patients. Bronson Vitamins have been consistently mentioned by top medical professionals since our inception in 1960.
Suitable for those whose vitamin D level is deficient or insufficient.
 
Dosage
Vitamin D3 – 125mcg (1 Softgel)
Vitamin K2 – 90mcg (1 Softgel)
 
Ratings
4.7 out of 5 – 11,636 global ratings
 
Reviews
I have been on a prescription of 50,000 IU once a week for years and I could not get my vitamin D levels over 30, which is not optimal, I started taking this and my levels were greater then 60 at my last lab report.. I stopped taking the script and am just doing this over the counter. The K2 is KEY. I have hashimotos and it’s critical that people get their vitamin D levels in the OPTIMAL range. Not just normal. I notice a huge difference in inflammation when I started taking the prescription and things have been much better since taking the vitamin d with K2. Highly recommend.

3. Now Foods Vitamin D3 & K2 (120 Veg Caps)

– Supports Bone Health
– Plus Cardiovascular Support
– Non-GMO
– Family Owned Since 1968
– GMP Quality Assured
 
Editor’s Note: Most of the Top 10 Vitamin D supplements as listed on the Amazon Best Sellers have dosages that exceed the maximum recommended dose (In USA and UK) of Vitamin D of 4,000 IU. Most of the brands also come in multiple dosages. Do check the label before you purchase.
 
Dosage
25mcg Vitamin D3 (1 capsule)
45mcg Vitamin K (1 capsule)
3mg Vitamin C (1 capsule)
 
Ratings
4.8 out of 5 – 5,079 global ratings
 
Reviews
Ordering second bottle now! Started take 2000mg along with magnesium. Hair loss stopped. No more mood Swings and no longer tired.

4. Zhou Nutrition Vitamin D3 And K2

Amazon Best Sellers Rank: #23 in Vitamin D Supplements.

Just one small, easy-to-swallow veggie capsule per day provides 5000 iu of D3 and 90 mcg of K2 as MK-7, helping you support strong bones and a healthy cardiovascular and immune system.

Vitamins K2 & D3 were simply meant to be together. Most people know the benefits of Vitamin D (maintaining strong bones, immune system support, healthy muscle function, etc.), but many don’t realize that Vitamin D NEEDS Vitamin K2 to maximize it’s benefits.
 
At Zhou, we use only the highest-quality ingredients in a facility following GMP (good manufacturing practices). Plus, we test everything at our lab in Utah, so you can be confident that you’re fueling your body with the very best.
 
STRONG BONES 
Vitamin D3 (termed the ‘sunshine vitamin’) is the same biologically active form of Vitamin D you get from the sun’s UVB rays. With this complex, you’ll get the benefits without the burn. D3 helps your body absorb the all-important calcium, and Vitamin K2 (as MK-7, the form of K2 with the highest bioavailability) directs the calcium to your bones instead of your joints and arteries, where too much calcium could be problematic.

HEALTHY HEART – 
If you’ve heard the term “hardening of the arteries”, it’s referring to calcification. Calcification occurs when calcium has been absorbed by the body, but deposited in arteries instead of bones. This formula not only promotes the proper absorption of calcium with D3, but the correct distribution to your bones where you need it most.
 
Dosage
Vitamin D3 – 125mcg (1 Softgel)
Vitamin K2 – 90mcg (1 Softgel)
 
Ratings
4.7 out of 5 – 6,534 global ratings

Reviews
I finished one bottle already and have ordered another. I had been taking 5000 IU Vit. D from a different brand and felt a lift in mood and general well-being. I expected to have similar results with this supplement, but have actually felt even better. I am very impressed with this supplement and highly recommend it to anyone suffering from depression, anxiety, and anyone over 50. If you haven’t asked your doctor about Vit D supplements, do so asap.

5. Mary Ruth's Vegan Organic Vitamin D3 + K2

– Liquid Spray by MaryRuth’s for Adults & Kids 
– Strong Bones, Heart Health, Calcium Absorption 
– Plant-Based, Non-GMO 
– 30 Servings (8 Sprays per serving) per Container 
– USDA Organic
 
Vitamin D3+K2 (MK-7)
Support Your Bones and Promote Heart Health with Our Organic D3 + K2 (MK-7) Spray. Help promote calcium absorption and support vitamin levels with this easy-to-take, vegan spray.
 
Multiple Benefits 
Calcium, Vitamins D and K2 are vital for bone health. Vitamin D is beneficial as it aids the body’s absorption of Calcium and Phosphorus and supports immune function. Vitamin K2 is also crucial for strong bones, but also for modulating Calcium — it activates osteocalcin which binds Calcium to bone; and it helps keep Calcium out of artery walls, where it doesn’t belong.
 
Per Serving (8 Sprays)
20 mcg (800 IU) Vitamin D3 (as Cholecalciferol); 80 mcg Vitamin K2 (as Menaquinone). Organic Olive Oil. 
 
Infants (0-12 Months) up to 4 Sprays (D3: 10 mcg; K2 MK7: 40 mcg). 
Children (1-13 Years) up to 6 Sprays (D3: 15 mcg; K2 MK7: 60 mcg).
Adults (14+ Years) up to 8 Sprays (D3: 20 mcg; K2 MK7: 80 mcg). 
Pregnant/Lactating up to 6 Sprays (D3: 15 mcg; K2 MK7: 60 mcg).
 
Easy-to-Take Liquid Spray
No more hard-to-swallow pills or capsules! Shake well before use. Once daily, take directly by mouth. Use our dosage chart to assess dosage or dose as recommended by physician or healthcare professional. Each bottle comes with 30 servings. Store in a cool, dry place.
 
Free of Common Allergens 
USDA Organic Vegan Vitamin D3+K2 (MK-7). Non-GMO, Vegan, Dairy Free, Nut Free, Gluten & Wheat Free, Soy Free, Corn Free, Nightshade Free, Sugar Free. Bariatric Friendly, Celiac Friendly, Keto Friendly, Kid Friendly.
 
Dosage
20 mcg Vitamin D3 / 80 mcg Vitamin K2 (8 sprays)
 
4.6 out of 5 – 1,717 global ratings
 
Reviews
This is the best alternative to chemical pills in case you have a deficit of vitamin D or you live in a not really sunny place. All the ingredient are organic and vegan, so it’s supernatural and suitable for everyone. The bottle comes with a spray nozzle, so when you spray it into your mouth it doesn’t go everywhere. The company is a small business with good principles and you can find their stories in the brochure inside the package.

6. Live Conscious Vitamin K2 MK7 with D3 Supplement

– 60 Capsules
– Bone & Heart Health Support
– Suitable for those whose vitamin D level is deficient or insufficient.
– Vitamin K2 MK-7 type, which research has shown to be best suited to achieve healthy bones and improved heart health. [clinicaltrials.gov].
 
Immune Booster: 
These two ingredients work together to strengthen your immunity. D3 plays a key role in activating an immune response to seek out foreign threats from invading your system.

Bone Health Support: 
Many people already know the benefits of vitamin D, including bone health and immune system support, but vitamin D needs K2 in order to be most effective, especially when fighting a vitamin D deficiency.

Boosts Healthy Blood Circulation: 
By ensuring that calcium gets where it needs to go, K2 promotes a cleaner overall circulatory system, as the calcium is better able to get where it needs to go.

Heart Healthy Formula: 
By fighting against the “hardening of arteries” due to calcification, this formula is a great way to promote heart health.
 
Dosage 
Vitamin D3 – 125mcg (1 Softgel)
Vitamin K2 – 100mcg (1 Softgel)
 
Ratings 
4.7 out of 5 – 2,110 global ratings

7. Organic Vitamin D3 K2 Drops with MCT Oil Omega 3 (Nusava) - Best Organic Vitamin D3 and K2 Supplement

Amazon Best Sellers Rank: #34 in Vitamin D Supplements.

Certified Organic Vitamin D: 
Certified organic by Natural Food Certifiers, our multi vitamin D drops to enhance your health naturally. Our D3 K2 Supplement Organic Liquid has no fillers, is non-GMO & proudly USA-made – ensuring high-quality goodness. We’ve carefully curated & sourced our ingredients so that you can replace all your other D & K vitamin supplements with just one small Nusava bottle to take wherever you go.

Liquid Vitamins Formulated for Maximum Potency: 
The Nusava K2 D3 Vitamin Supplement 5000 IU with MCT Oil and Omega 3 provides amazing support for a healthier mind and body. With 125mcg (5000 IU) of Vitamin D3, 120mcg of Vitamin K, 250mcg of Omega 3, and a blend of organic ingredients including MCT oil, flaxseed oil, and olive oil, the Nusava Vitamin D Liquid Drops for adults will definitely be your next holy grail supplement.

Tons of Benefits in Every Drop: 
Nusava makes living healthier more convenient for people with demanding lifestyles, that’s why we created 4-in-1 vitamins that have a multitude of benefits in every serving – ridding the need to purchase different bottles for different ingredients. With our potent blend, we make it convenient for you to get all the necessary mind, body, and heart-healthy nutrients for a stronger lifestyle.

Liquid Vitamin D for Faster Absorption: 
Liquid vitamins take effect quickly and are more readily absorbed by the body, making it more potent than capsules or tablets. Moreover, most people (such as the young and elderly), tend to find it difficult to swallow pills. With our blend of liquid Omega 3, MCT Oil, and K2 D3 vitamin supplement, you don’t have to worry about the difficulty of swallowing lots of capsules after every meal.
 
Dosage
Vitamin D3 – 125mcg (1 Softgel)
Vitamin K2 – 120mcg (1 Softgel)
 
Ratings
4.4 out of 5 – 2,490 global ratings

Reviews
I like that it contains 3 supplements in one bottle. I have SAD and this helps with my depression. The liquid form is fast acting so it is a must. The flavor is not so bad and not so good either. But that’s the omega 3. I will buy again.

FAQ

Vitamin D needs to undergo two conversion steps to become active (SourceSource).

 

First, it is converted to calcidiol, or 25(OH)D, in your liver. This is the storage form of the vitamin.

 

Second, it is converted to calcitriol, or 1,25(OH)2D, mostly in your kidneys. This is the active, steroid-hormone form of vitamin D.

 

 

Calcitriol interacts with the vitamin D receptor (VDR), which is found in almost every single cell in your body (Trusted SourceTrusted Source).

When the active form of vitamin D binds to this receptor, it turns genes on or off, leading to changes in your cells. This is similar to how most other steroid hormones work (Trusted SourceTrusted Source).

 

Vitamin D affects various cells related to bone health. For example, it promotes the absorption of calcium and phosphorus from your gut (Trusted Source).

 
But scientists have recently discovered that it also plays roles in other areas of health, such as immune function and protection against cancer (Source).
Vitamin D3 dan D2

In fact, vitamin D3 supplements appear to be more effective at raising vitamin D levels than D2 supplements. 

 

Vitamin D ensures that your blood levels of calcium are high enough to meet your body’s demands. However, vitamin D does not fully control where the calcium in your body ends up. That’s where vitamin K steps in. Vitamin K2 supplements have been proven to be more effective than vitamin K1. That’s why most of the top vitamin D supplement brands do combine their vitamin D3 with K2.

Vitamin D deficiency is one of the most common nutrient deficiencies.


Some people are at a greater risk than others. In the United States, 41.6% of the total population is deficient, although minorities fare worse — 82.1% and 69.2% of blacks and Hispanics are deficient, respectively (Trusted Source).


Additionally, older adults are at a much greater risk of being deficient (Trusted Source).


Those who have certain diseases are also very likely to be deficient. One study showed that 96% of people who had experienced heart attacks were low in vitamin D (Trusted Source).


Overall, vitamin D deficiency is a silent epidemic.

The symptoms are usually subtle and may take years or decades to surface.


The most well-known symptom of vitamin D deficiency is rickets, a bone disease common in children in developing countries.


Rickets has been mostly eliminated from Western countries because of the fortification of some foods with vitamin D (Trusted Source).


Deficiency is also linked to osteoporosis, reduced mineral density, and increased risk of falls and fractures in older adults.


What’s more, studies indicate that people with low vitamin D levels have a much greater risk of heart disease, diabetes (types 1 and 2), cancer, dementia, and autoimmune diseases like multiple sclerosis (Trusted Source).


Finally, vitamin D deficiency is linked to a reduced life expectancy (Trusted SourceTrusted SourceTrusted Source).


That said, it’s unclear whether deficiency contributes to these diseases or whether people with low levels are just more likely to get them.
Half of adults over 50 years of age have low bone mass. Bone health is a real concern as we get older. Fortunately, the pairing of vitamin D3 and K2 seems to improve bone health across the board.
 
You can further minimize your vitamin D requirement by making sure you’re also getting enough magnesium. Magnesium is required for the conversion of vitamin D into its active form and research has confirmed higher magnesium intake helps reduce your risk of vitamin D deficiency by activating more of it. 
 
Taking both magnesium and vitamin K2 can lower your vitamin D requirement.
 

Eggs (44 IU per egg), along with fortified foods including milk and some cereals are excellent sources. 

Do take note that you can also get good amounts of vitamins C and D, zinc and other essential vitamins and minerals from a basic multivitamin. If you are taking a multivitamin, your D-vitamin needs may be covered, but be careful not to let the total exceed 4,000 IU or 100 mcg.

To maintain healthy levels, only 400 to 800 IU (15 to 20 mcg) of vitamin D is required daily, but, to boost low levels, higher doses, such as 2,000 IU daily, are used and are generally safe.

 
A group of researchers from the US, UK, Netherlands and New Zealand, said that the RDA of vitamin D should be increased to 2,000 IU and vitamin C to 200 mg in their review published in Nutrients 2020.

 

In recent weeks and months, there’s been an upshot of studies demonstrating the benefits of vitamin D against COVID-19. The evidence is so compelling, more than 100 doctors, scientists and leading authorities have signed an open letter calling for increased use of vitamin D in the fight against COVID-19.

 
Based on several publications and studies, vitamin D seems to be the “most promising” supplement for COVID-19 protection. Vitamin D deficiency is known to enhance a process known as the “cytokine storm” (NIH).
 

Trusted Source).

There are many vitamin D studies underway. You can review the status of these trials on clinicaltrials.gov. As of April 2021, more than 70 studies have been launched to investigate the benefits of vitamin D against COVID-19.
 
Two studies in France (C Annweiler, Nov 2020G Annweiler, Nov 2020), one in India (A Rastogi, Nov 2020) and one in Spain (M Castillo, Oct 2020) showed that Vitamin D supplementation seems to decrease the mortality rate, the severity of the disease, and the inflammatory markers’ levels among the COVID-19 infected patients, leading to a better prognosis and increased survival.
 

The largest observational study to date, looked at data for 191,779 American patients who were tested for SARS-CoV-2 between March and June 2020 and had had their vitamin D tested sometime in the preceding 12 months.

Of those with a vitamin D level below 20 ng/ml (deficiency), 12.5% tested positive for SARS-CoV-2, compared to 8.1% of those who had a vitamin D level between 30 and 34 ng/ml (adequacy) and 5.9% of those who had an optimal vitamin D level of 55 ng/ml or higher.

 

Data from 14 observational studies — suggest that vitamin D blood levels are negatively correlated with the incidence and/or severity of COVID-19; meaning if your vitamin D level is high, your risk for COVID-19 is low and vice versa.


A study published in November 2020 from Singapore (CW Tan, Nutrition 2020) – 
Found that those who were started on a daily oral dose of vitamin D3 (1,000 IU), magnesium (150 mg) and vitamin B12 (500 mcg) within the first day of hospitalisation and continued up to 14 days were significantly less likely to require oxygen therapy and further intensive care.

Another study, published in JAMA (JAMA Netw Open – Sep 2020) found that persons who are likely to have deficient vitamin D levels at the time of COVID-19 testing were at substantially higher risk of testing positive for COVID-19 than were persons who were likely to have sufficient levels.


The same team above, has also published a preprint article: A study at the University of Chicago of over 4,000 patients that found that untreated vitamin D deficiency was associated with an increased risk for COVID-19 infection.

 
study of 20 European countries found a link between low levels of vitamin D and higher percentages of COVID-19 cases and mortality. 
 
Separately, more than 80% of 200 people hospitalized for COVID-19 in Spain were found to be deficient in vitamin D, according to a study published in October in the Journal of Clinical Endocrinology & Metabolism.

How much vitamin D3 should I take? The RDI for vitamin D is as follows (NIH):

  • 400 IU (10 mcg): infants, 0–12 months
  • 600 IU (15 mcg): children and adults, 1–70 years old
  • 800 IU (20 mcg): older adults (seniors) and pregnant or breastfeeding women
Do take note that you can also get good amounts of vitamin D and other essential vitamins and minerals from a basic multivitamin and milk formula. Always inform your doctor on the kind of supplements that you are taking as your doctor might also prescribe supplements for you that might lead to overdosing or duplicates.
In the US, current guidelines suggest that consuming 400–800 IU (10–20 mcg) of vitamin D should meet the needs of 97–98% of all healthy people (Trusted Source).

However, many experts believe the guidelines are far too low (Trusted Source).

Your vitamin D needs depend on a variety of factors. These include your age, skin color, current blood vitamin D levels, location, sun exposure and more.

To reach blood levels linked to better health outcomes, many studies have shown that you need to consume more vitamin D than the guidelines recommend (Trusted SourceTrusted SourceTrusted Source).

For instance, an analysis of five studies examined the link between vitamin D blood levels and colorectal cancer (Trusted Source).

Scientists found that people with the highest blood levels of vitamin D (over 33 ng/ml or 82.4 nmol/l) had a 50% lower risk of colorectal cancer than people with the lowest levels of vitamin D (less than 12 ng/ml or 30 nmol/l).

Research also shows that consuming 1,000 IU (25 mcg) daily would help 50% of people reach a vitamin D blood level of 33 ng/ml (82.4 nmol/l). Consuming 2,000 IU (50 mcg) daily would help nearly everyone reach a blood level of 33 ng/ml (82.4 nmol/l) (Trusted SourceTrusted SourceTrusted Source).
 
According to Dr John Campbell:
  • Deficiency: Less than 20 ng/ml (50 nmol/L)
  • Insufficiency: 21 – 29 ng/ml (52 – 72 nmol/L)
  • Sufficiency: More than 30 ng/ml (75 nmol/L)
Another analysis of seventeen studies with over 300,000 people looked at the link between vitamin D intake and heart disease. Scientists found that taking 1,000 IU (25 mcg) of vitamin D daily reduced heart disease risk by 10% (Trusted Source).

Based on current research, it seems that consuming 1,000–4,000 IU (25–100 mcg) of vitamin D daily should be ideal for most people to reach healthy vitamin D blood levels.
 
However, don’t consume more than 4,000 IU of vitamin D without your doctor’s permission. It exceeds the safe upper limits of intake and is not linked to more health benefits (Trusted Source).

Vitamin D is a fat-soluble vitamin, meaning that it does not dissolve in water and is absorbed best in your bloodstream when paired with high-fat foods.

For this reason, it’s recommended to take vitamin D supplements with a meal to enhance absorption.

According to one study in 17 people, taking vitamin D with the largest meal of the day increased vitamin D blood levels by about 50% after just 2–3 months (NIH).

In another study in 50 older adults, consuming vitamin D alongside a fat-heavy meal increased vitamin D blood levels by 32% after 12 hours compared to a fat-free meal (NIH).

Avocados, nuts, seeds, full-fat dairy products and eggs are nutritious sources of fat that help boost your vitamin D absorption.

Here is the vitamin D3 content of a few of the best food sources (NIH):
FoodAmount% RDI
Cod liver oil, 1 tablespoon (15 ml)1,360 IU / 34 mcg227%
Salmon, cooked, 3 ounces (85 grams)447 IU / 11 mcg75%
Tuna, canned in water, 3 ounces (85 grams)154 IU / 4 mcg26%
Beef liver, cooked, 3 ounces (85 grams)42 IU / 1 mcg7%
1 large whole egg (D is found in yolk)41 IU / 1 mcg7%
1 sardine, canned in oil, drained23 IU / 0.6 mcg4%
 

Although fatty fish like salmon, mackerel, swordfish, trout, tuna, and sardines are decent sources, you would have to eat them almost every day to get enough.

The only excellent dietary source of vitamin D is fish liver oil — such as cod liver oil — which contains upwards of two times the Reference Daily Intake (RDI) in a single tablespoon (15 ml).

Keep in mind that dairy products and cereals are often fortified with vitamin D (NIH).

Some rare mushrooms also harbor vitamin D, and egg yolks contain small amounts.

Two studies in France (C Annweiler, Nov 2020G Annweiler, Nov 2020), one in India (A Rastogi, Nov 2020) and one in Spain (M Castillo, Oct 2020) showed that Vitamin D supplementation seems to decrease the mortality rate, the severity of the disease, and the inflammatory markers’ levels among the COVID-19 infected patients, leading to a better prognosis and increased survival.

Annweiler et al.: All residents in the nursing-home receive chronic vitamin D supplementation with regular maintenance boluses (single oral dose of 80,000 IU vitamin D3 every 2–3 months), without systematically performing serum control test as recommended in French nursing-homes due to the very high prevalence of hypovitaminosis D reaching 90–100 % in this population.
 
Rastogi et al.: Participants were randomised to receive daily 60 000 IU of cholecalciferol (oral nano-liquid droplets) for 7 days with therapeutic target 25(OH)D>50 ng/ml (intervention group) or placebo (control group).
 
Castillo et al.: Eligible patients were allocated at a 2 calcifediol:1 no calcifediol ratio through electronic randomization on the day of admission to take oral calcifediol (0.532 mg), or not. Patients in the calcifediol treatment group continued with oral calcifediol (0.266 mg) on day 3 and 7, and then weekly until discharge or ICU admission. Outcomes of effectiveness included rate of ICU admission and deaths. Do take note that 0.25 mg is equivalent to 10,000 IU.
 
Editor’s NoteVitamin D Upper Limit is 4,000 IU per day. The above dosages of vitamin D are NOT your normal maintenance dosage and are done under medical supervision and clinical trial setting. Do not self-medicate at this dosage!