Best vitamin D supplements for boosting your immune system

Support your mood and give your immune system a boost with the best vitamin D supplements, tried and tested

woman taking a dietary supplement with water
(Image credit: Getty images)

The best vitamin D supplements can provide a wealth of health benefits. Also known as the sunshine vitamin, vitamin D is essential for helping the immune system to fight bacteria and viruses. Alongside calcium, it also supports bone health and prevents osteoporosis, whilst studies show that low blood levels of vitamin D are linked to an increased risk of depression. This is because vitamin D is necessary for your brain to function properly.

Yet vitamin D is one of the most common vitamin deficiencies. According to a study published in Nutrition Research (opens in new tab), 42% of Americans are deficient in vitamin D, with it being even more prevalent in black and Hispanic populations.

There are a few ways to increase your vitamin D intake. One is by making sure that you have adequate exposure to sunlight every day. This is because when the sun’s ultraviolet (UV) rays come into contact with the skin, it triggers vitamin D synthesis. You should include plenty of vitamin D foods in your diet too, including oily fish, eggs, fortified mushrooms and breakfast cereals.

However, you might struggle to get enough vitamin D from diet alone, especially if you’re a fussy eater or you follow a plant-based diet. If you’re someone who spends long periods of time indoors, you may also find it difficult to manufacture enough vitamin D from sunlight. That’s where the best vitamin D supplements come in. In this guide, we’ll be discussing everything from the ingredients to the packaging, as well as user reviews, so you can decide which vitamin D supplement suits your needs.

What strength should your vitamin D supplement be?

There are two forms of vitamin D found in foods and supplements:

  • Vitamin D2 (ergocalciferol)
  • Vitamin D3 (cholecalciferol) 

Of the two, D3 is the most bioavailable form, and raises vitamin D levels almost twice as much as D2. When looking for a vitamin D supplement, it’s better to opt for one that contains D3 over D2.

According to the National Institutes of Health (opens in new tab), anyone over the age of one should be getting at least 600 IU (15 mcg) of vitamin D per day, rising to 800 IU (20 mcg) for those over the age of 70. However, recommendations do vary between countries. In the UK, for example, the government recommends an intake of 400 IU (10 mcg) for those aged four and over.

However, some studies suggest that an intake of 1,000-4,000 IU (25-100 mcg) is needed to maintain optimal blood levels. It’s worth checking with your doctor to see what your blood serum levels are, as this will determine the strength of the supplement you take. Those with a diagnosed deficiency may need a higher dose. Factors such as age and skin color also make a difference, as those with darker skin tend to absorb less vitamin D from the sun.

Since vitamin D is a fat-soluble vitamin, it can be helpful to take the best vitamin D supplement alongside a source of dietary fat, such as Greek yogurt, olive oil, oily fish or avocado. This may help with absorption. 

The best vitamin D supplements you can buy right now

Ancient Nutrition vitamin d supplementFit&Well Awards: Editor's Choice

(Image credit: Alice Ball)

Ancient Nutrition Vitamin D

Best vitamin D supplement overall

Specifications

Recommended dosage: 1 capsule per day
Vitamin D per dosage: 5,000 IU
Suitable for vegans: No
Capsules per unit: 60
Easy to swallow: Yes

Reasons to buy

+
Tasteless
+
Contains added adaptogens 

Reasons to avoid

-
Not suitable for vegans
-
Pills on larger side

Ancient Nutrition is a relatively new supplement brand that creates products based on the principles of Ayurveda and Traditional Chinese Herbalism, in combination with modern science. Its vitamin D capsules come in a sleek black pot (inside a box) with yellow and white accents.

Ancient Nutrition vitamin D has 60 capsules, each of which contain 5,000 IU (125 mcg) of vitamin D, as well as 3,000 IU (90 mcg) of vitamin K, which is 625% and 75% of your daily recommended intake, respectively. It also contains the brand’s ‘TCM (Traditional Chinese Method) blend’, which aims to “bring a holistic approach to your daily vitamin D supplement” in order to “support the body as a complete system rather than separate organs, a larger concept down as ‘QI’”. This blend uses a combination of bovine liver, organic astragalus extract, beef bone broth, chicken bone broth, organic schisandra berry extract and more. The brand claims its product is formulated for “real food, Paleo and keto enthusiasts”, although it is obviously not suitable for vegetarians or vegans because of the ingredients used in the TCM blend.

What the users say:

Users seem to love Ancient Nutrition vitamin D, with one user noting that “not many companies produce 5,000 IU in one capsule together with vitamin K2”. Others, like us, enjoy that the capsules are tasteless and use high quality ingredients. Negative reviews are hard to find, but some users reserve giving the product the full five stars based on its higher price tag.

At $29.95 for 60 capsules, this isn’t the cheapest option in our round-up. However, the capsules are tasteless and easy to swallow (despite being on the larger side). Plus, if you’re interested in adding TCM to your diet, and require a higher dose of vitamin D, you might want to give them a try.


now foods chewable vitamin d supplement

(Image credit: Alice Ball)

Now Foods Chewable Vitamin D

Best vitamin D supplements on a budget

Specifications

Recommended dosage: 1 tablet
Vitamin D per dosage: 1,000 IU
Suitable for vegans: No
Capsules per unit: 180

Reasons to buy

+
Ideal for those that can't swallow tablets
+
Wallet-friendly

Reasons to avoid

-
Dosage may not be high enough for those with a deficiency 
-
Slightly artificial taste

NOW Foods is a respected, family-owned company that has been operating in the US since 1968. Its mission has been “to provide value in products that empower healthier lives”. Its chewable vitamin D tablets come in a white pot, with a purple and orange label.

Each chewable contains 1,000 IU of vitamin D3, which is 125% of your daily value. However, if 1,000 IU isn’t sufficient for you, the product is available in 5,000 IU potency as well, although do note that this is in mint flavor, rather than natural fruit.

Obviously a draw of Now Foods chewable vitamin D is that you don’t need to swallow any capsules, making this an ideal supplement for people who don’t like taking medication. At around $7.54 for 180 tablets, this is a really good value option too. Plus, the tablets are absolutely tiny, so you can chew one up in no time.

What the users say:

On iherb, the product scores 4.9 out of five stars. One customer wrote: “I actually like the light taste of these chewables. The size of the pill is small, which is nice. The dose is also good for someone like myself who has been taking supplements for a while and wants to maintain a reasonable level of vitamin D.” Amazon users also rate the product 4.7 out of five. On the whole, they enjoy the taste, but there are a couple who find them slightly too sweet and artificial.

Whilst Now Foods vitamin D is dairy free, egg free, halal, josher, nut free, soy free and made without gluten, they are not suitable for vegans because the D3 is derived from sheep’s wool (lanolin). 


Throne vitamin D and K2 liquid drops

(Image credit: Alice Ball)

Thorne Vitamin D & K2

Best liquid vitamin D supplement

Specifications

Recommended dosage: Two drops, one to three times daily
Vitamin D per dosage: 1,000 IU
Suitable for vegans: No
Capsules per unit: 600

Reasons to buy

+
Can be easily added to food
+
One unit lasts 20 months

Reasons to avoid

-
Dropper can be awkward to work
-
Not suitable for vegans

Thorne is a trusted supplement company whose ambition is to “empower individuals for longer through personalized scientific testing and solutions”. Its vitamin D and K2 liquid supplement comes in a small brown bottle with white, gold and black accents on the label. 

Each bottle contains 600 servings, with two drops providing 1,000 IU vitamin D3 and 200 mcg of vitamin K2 – that’s 125% and 167% of your recommended daily value, respectively. According to Thorne, “combining vitamins D and K can provide greater support of the immune and cardiovascular systems than each offers separately”. It also claims the supplement “supports healthy bones and muscles, as well as the cardiovascular system and immune systems”. 

Because this is a liquid supplement, you can drip it straight onto a spoon, into your mouth, or put it into drinks or on your food. It’s ideal for those who can’t or dislike swallowing tablets. The dropper is a slightly unusual design, so can take a bit of getting used to using.

What the users say

The product scores an impressive 4.7 stars out of five on Amazon. One user wrote: “Have been using this product for some time now and it works great. Has no flavor at all, they are easy to swallow as it is liquid. However, it is a little difficult to dispense the drops. I feel like a dropper would be much better.” Other users also note that the dropper makes it difficult to dispense the drops. However, complaints about the actual quality of the product are rare.

At around $23.40 per bottle, this product might not appear the most affordable. However, if you use two drops per day it will last you around 20 months, making this good value for money. 


HUM here comes the sun vitamin d supplement

(Image credit: Amazon)

HUM Here Comes The Sun

Best vitamin D supplement for vegans

Specifications

Recommended dosage: One softgel
Vitamin D per dosage: 2,000 IU
Suitable for vegans: Yes
Capsules per unit: 30

Reasons to buy

+
Vegan-friendly
+
Easy to swallow

Reasons to avoid

-
Not as budget-friendly
-
Dose may be too high for some individuals

You might be surprised to learn that many of the best vitamin D supplements are not suitable for vegans. This is because they rely on animal-based sources of vitamin D3 such as the skin of fatty fish or lanolin from sheep’s wool. Whilst some plants and fortified plant-based foods contain small amounts of vitamin D, this tends to be D2. Research suggests that vitamin D3 is more important for supporting healthy levels of vitamin D.

Luckily, supplement brand HUM Nutrition has formulated a fully-vegan dietary supplement that provides 2,000 IU of vitamin D3 – that’s 250% of your daily value. Its Here Comes The Sun supplement uses lichen, an algae-fungal hybrid microorganism that grows on trees and stones. This is the only plant that contains vitamin D in its most available form – vitamin D3. 

Each pot contains 30 vegan softgels, and comes with a bright yellow label on a black bottle. Bear in mind that because Here Comes The Sun contains 2,000 IU of vitamin D, you may want to be careful if you’re taking them in combination with a standard multivitamin. Some of these can contain similar levels of vitamin D, which may push you near to the upper limit of 4,000 IU per day.

HUM Nutrition prides itself on producing mostly vegetarian products, and “in cases where there is a lack of a plant based alternative, [they] work actively with [their] suppliers on developing one”. All of its products are made in facilities that are certified to follow GMPs (Good Manufacturing Processes), required by the FDA. They are also gluten-free and non-GMO.

What the users say:

On the manufacturer’s website, the capsules score 4.6 stars. One user wrote: “I like that the capsules are small and easy to take. I definitely notice a difference when I don’t take Here Comes The Sun daily.” Another wrote: “I live in a more northern state in the US and we don’t always get sunny days. Taking this has made huge improvements to my mood”. 

At $12 for a month’s supply, these aren’t the cheapest vitamin D supplements, but they’re certainly not the most expensive either. And given the quality of the ingredients – plus the fact that they’re suitable for vegans – they seem a good deal.


Ritual Essential Women's Prenatal Multivitamin

(Image credit: Alice Ball)

Ritual Essential Prenatal Multivitamin

Best vitamin D supplement for prenatal women

Specifications

Recommended dosage: Two capsules
Vitamin D per dosage: 2,000 IU
Suitable for vegans: Yes
Servings per unit: 30

Reasons to buy

+
Contains 11 other key nutrients
+
Vegan-friendly

Reasons to avoid

-
Expensive
-
Taste might not be to everyone's liking

Pregnant women may require higher doses of some vitamins, including vitamin D, from conception or early pregnancy. This is because, according to Cochrane findings, evidence shows that vitamin D supplementation probably reduces common risks associated with pregnancy, including pre-eclampsia and gestational diabetes, and may reduce the risk of having a low-birthweight baby or bleeding after birth. 

Ritual is a popular supplement brand that promises to bring you ethical, vegan vitamins with traceable ingredients. Its Prenatal Multivitamin comes in clear, minimalistic packaging and the capsules themselves have little gold ‘beadlets’ and visible liquid.

Two capsules contain an impressive 2,000 IU of vitamin D, as well as a host of other nutrients to support a healthy and happy pregnancy, including folate, omega-3 DHA, vitamin B12, iodine, iron and magnesium. So if you’re a mum-to-be who doesn’t want to have to take a load of different supplements, this is a great option for you. The capsules are also essenced with lemon, by use of a citrus tab in every bottle. This helps to keep things fresh, and ensures no weird taste that some capsules can have. 

As well as the Prenatal Multivitamin, Ritual sells a standard women’s multivitamin that also contains a host of ingredients to support your mind and body – including vitamin D.

What the users say:

Reviews for Rituals Prenatal Multivitamin are largely very positive. However, some customers do note that the lemon scent can be slightly unpleasant during pregnancy, especially if you’re struggling with morning sickness. They would prefer the mint flavor of the standard women’s multivitamin. However, one user wrote: “I’ve been taking this prenatal while trying to conceive my third baby and it’s been easy to take, easy on my stomach, and tastes great. I was definitely skeptical but they had more nutritional value than the other prenatal vitamins I was taking. Love them.” 

At $35 per pot (lasting you one month) these are not the cheapest vitamin D supplement, but they contain high quality ingredients and you’re getting a variety of nutrients for your money.


double wood supplements vitamin d + k2 liquid drops

(Image credit: Getty Images)

Double Wood Supplements Vitamin D3 + K2 Liquid Drops

Best high-strength vitamin D drops

Specifications

Recommended dosage: 1 ml
Vitamin D per dosage: 5,000 IU
Suitable for vegans: No
Servings per unit: 30

Reasons to buy

+
Dropper easy to use
+
Relatively tasteless

Reasons to avoid

-
Strength may be too high for some individuals

Double Wood Supplements was founded by two brothers in 2013, and has since expanded its product range to include “a wide range of niche supplements intended for brain health, anti-aging, immune support and more”. Each of its products is supported with third party testing, and the brand claims to settle for “nothing less than the best quality” at “an affordable price”. 

Its Vitamin D3 + K2 Liquid Drops are perhaps one of the lesser “niche supplements” they offer, and come in a small brown bottle with the brand’s green and neutral toned label. 

One drop (1 ml) of the product contains 5,000 IU of vitamin D (625% of your daily value) and 200 mcg of vitamin K2 (167% of your daily value), making this a great product for those who require a higher dose of vitamin D.

What the users say:

Double Wood Vitamin D3 + K2 Liquid Drops score an impressive 4.7 out of five stars on Amazon. Users like that it is really easy to take, with one noting: “I drop this in my coffee and I’m good to go!” Most users have no trouble with the medicine dropper either (unlike some other brands) and note that the liquid has no foul taste or odor.

The brand also claims to use the “all-trans version of K2 (K2 Vital)” which they say is “much more effective than the cheaper cis-K2 variety” as well as “an MCT oil base providing plenty of fat for proper absorption”. This means that it is not necessary to take the product with food. However, we found it much easier to add 1 ml to our morning oatmeal or hot drink, rather than load it onto a spoon or straight into our mouth. It’s fairly tasteless, but it does have a hint of tartness to it, so we found this a more pleasant way to integrate it into our supplement routine.

Why take a vitamin D supplement?

Vitamin D is an essential part of any diet, and many people can benefit from taking a vitamin D supplement. 

The following groups in particular are among those most likely to have inadequate vitamin D status:

  • Breastfed infants
  • Older adults
  • People with limited sun exposure
  • People with darker skin
  • People with obesity or who have undergone gastric bypass surgery 

So what exactly is vitamin D good for? For one, it’s critical for brain health. One review of 14 studies published in The British Journal of Psychiatry (opens in new tab) found an association between deficient or low levels of vitamin D and depression. Among postmenopausal women and older men, many clinical trials have also shown that supplements of both vitamin D and calcium results in small increases in bone mineral density throughout the skeleton. Not to mention, low levels of vitamin D have been linked to an increased risk of heart diseases such as hypertension, heart failure and stroke, according to a review in the Journal of Endocrinology Investigation (opens in new tab).

How we tested

Each of the products included in this guide was tested by the Fit&Well team. Supplements will affect each and every person slightly differently so we’ve been using these vitamins to give you a better idea of what they contain, and anything you need to be aware of before taking them. Below are the criteria we tested each product for. 

Ingredients

It’s super important to us that you know exactly what we tested and why and our first starting point is always to find out exactly what ingredients are in a vitamin D supplement, especially if it’s a multivitamin. We then compare this against your daily recommended dosage and decipher whether you can get enough vitamin D from these supplements. 

Recommended dosage

We made sure to note how much of each supplement you are required to take and how much often. This gave us a clear indication of whether a product offered good value for money or not.

Suitability 

Not all vitamins and supplements will be suitable for everyone which is why we take note of whether a vitamin D supplement is suitable for vegans or have gluten-free diets. 

Cost and value for money 

Getting the nutrients you need shouldn’t have to cost any more than necessary so we compared pricing across all the vitamin D supplements we tested to see whether the more expensive capsules were worth the money and if the cheaper supplements still contain everything you need.  

Easiness to swallow & taste

For some, taking capsules or tablets can be very challenging so we test each and every vitamin D supplement by taking them ourselves and observing how easy they are to swallow. Some supplements are dissolvable on your tongue so we time how long this process takes.

The taste, while subjective, is another important factor we test. We try each capsule and note down whether they taste like the intended flavor or anything else you may need to know about after tastes too.

Features

When we test vitamin D supplements, we note anything that makes one supplement stand out over the others. We ask if any of the supplements claim to do something that others don’t, and we also consider the overall aesthetics of the product.

Alice Ball
Alice Ball

Alice Ball is the Health Editor for Future Plc. With more than five years of experience working in health journalism, she's covered everything from why we should 'kill' the calorie, to destigmatizing the menopause. Alice also specializes in nutrition and supplements. She's a self-confessed running fanatic, currently in training for her fifth marathon. She enjoys documenting her progress on her Instagram account, @aligoesrunning. Alice works across a number of Future's sites, including LiveScience and Fit&Well.