- Vitamin D is required for calcium absorption and the regulation of serum calcium and phosphorus for bone health along with helping to regulate inflammation, cell growth, and immune function
- Dietary forms of vitamin D include vitamin D2 from plants and vitamin D3 from animals which also contains the highest absorption rate and is often the type found in vitamin supplements
- Some green powders can be used in place of a multivitamin with vitamin D, such as Human Tonik’s Supergreen Tonik because of its high vitamin and mineral content and optional vegan blend that uses vitamin D2 from plant sources
Vitamin D is an essential fat-soluble vitamin that has recently been recognized for its role in preventative health.
In the early 2000s, various research studies were able to link lower levels of vitamin D, even those considered within the normal range, to be a risk factor for various conditions including cancer, diabetes, and mental health disorders. (Source)
This new research, along with the increased use of sunscreen, left many consumers concerned about their vitamin D levels.
Because sun exposure presents its own health concerns, many people aren’t getting adequate exposure to sunlight which is one of the best ways to increase your vitamin D levels.
The Role Of Vitamin D
Although this vitamin has gained the spotlight in recent years, it has always been known to play an important role in your bone and immune health.
Vitamin D, also known as calciferol, is required for calcium absorption and the regulation of serum calcium and phosphorus for bone health.
Without it, our bones can become brittle and increase our risk of developing conditions such as osteoporosis. Vitamin D also plays a role in regulating inflammation, cell growth, and immune function. (Source)
Types Of Vitamin D
Vitamin D can be found in three different forms. The best form of vitamin D is the form that is synthesized from direct exposure to sunlight.
Dietary forms of vitamin D include 2 types, vitamin D2, and vitamin D3. Vitamin D2, also known as pre-vitamin D or ergocalciferol, can be naturally found in plants and fungi. Vitamin D3, also known as cholecalciferol, can be found in animal sources. There is also vitamin D4, which is present in some mushrooms but is relatively rare. (Source)
Vitamin D vs Vitamin D3
Vitamin D absorption from sunlight varies from person to person depending on a variety of factors. Use of SPF sunscreen, clothing, darker skin tones, older age, and geographical location can all affect the amount of vitamin D absorbed by the skin.
For example, older adults are more likely to spend more time indoors and have decreased levels of 7-dehydrocholesterol levels which are required to synthesize vitamin D from sunlight.
Additionally, those who wear sunblock or excessive clothing that covers most of their body while outdoors will have less exposure to UV rays for vitamin D absorption.
Those who live in areas that are farther from the equator have weaker UV rays and often cooler temperatures which can affect the amount of vitamin D available to be absorbed. (Source)
When it comes to oral vitamin D supplements, vitamin D3 appears to have a better absorption rate than vitamin D2 according to research. This is because vitamin D2 mainly comes from plant sources and is not as successful at raising vitamin D levels in the body.
Vitamin D is a fat-soluble vitamin which means vitamin D supplements are absorbed best in the presence of fat. This can be as simple as pairing your vitamin D supplement with a meal that contains fat. Healthy fats such as avocado, salmon, olive oil, nuts, and seeds are recommended.
Sources Of Vitamin D
The best source of vitamin D comes from exposure to sunlight. Getting adequate amounts takes regular exposure to the sun.
The best way to ensure you are getting enough vitamin D from sun exposure is to get outside regularly during midday for at least 10-30 minutes several times per week.
For those who have a darker complexion, more time in the sun may be needed. Likewise, those who are fair-skinned and sensitive to sun exposure should aim closer to 10 minutes to avoid sunburn.
You can also get vitamin D from various foods and supplements.
Vitamin D can be found naturally in many foods, and it can also be added to foods in the form of fortification, which occurs when manufacturers add specific nutrients to food. Foods that are commonly fortified include dairy products, cereal, and orange juice.
The best sources of vitamin D2 and D3 include:
- Fish (salmon, sardines, herring, tuna)
- Cod liver oil
- Beef liver
- Egg yolk
- Shellfish (shrimp)
- Certain mushrooms including those treated with UV light.
- Fortified dairy (milk, yogurt)
- Fortified cereal
- Fortified orange juice
Vitamin D4 can be found in supplements and various mushrooms but these are less common.
Vitamin D Supplementation
If you fall under the category of people who likely have low vitamin D levels or have recently had your vitamin D levels tested and discovered they were low, a supplement may be a good route to take.
Before choosing a supplement, consider the type of vitamin D you wish to choose.
Vitamin D vs D2 And Vitamin D vs D3
The biggest difference between vitamin D and vitamin D3 is that vitamin D is the fat-soluble vitamin that we obtain from exposure to sunlight. This is the vitamin that is responsible for calcium regulation.
Vitamin D3 is the natural form of vitamin D that is produced by the body. This is why vitamin D3 is the best source of vitamin D in supplements to successfully raise vitamin D levels in the body.
The same goes for vitamin D versus vitamin D2. Vitamin D2 performs the same roles in the body as vitamin D3 but is not as readily absorbed.
Vitamin D2 is often still found in supplements because it is vegan-friendly, and it is more widely available in larger doses than vitamin D3.
Vitamin D3 vs Vitamin D2
As mentioned above, vitamin D3 comes from animal sources and vitamin D2 comes from plants.
Although vitamin D3 is considered the best form for absorption rates to increase your body’s total vitamin D levels, that doesn’t mean that taking vitamin D2 supplements does not have any benefits.
In fact, vitamin D2 supplements are the best option for those following a vegan or vegetarian diet.
If you struggle with your vitamin D levels and aren’t following a plant-based diet, vitamin D3 may be the best option for you; however, both forms of vitamin D can be used to improve deficiency.
Individual Vitamins vs Multivitamins
If you are struggling with a vitamin D deficiency, an individual vitamin supplement for vitamin D vs a multivitamin is likely all you need.
However, if you constantly struggle with low vitamin D levels and have some concerns about other nutrients, such as calcium and phosphorus, you may consider a multivitamin or a green powder.
Green Powders vs Multivitamins
Multivitamins are supplements that contain an array of vitamins and minerals meant to help fill in any nutritional gaps in your diet.
Green powders are a type of supplement that contain a mixture of fruits, vegetables, and herbs that are dried into powdered form.
Some green supplements can be used in place of a multivitamin, such as Human Tonik’s Supergreen Tonik because of their high vitamin and mineral content.
This product also contains 100% of the daily value (DV) for ergocalciferol (vitamin D2)
However, this is not true for all green powders.
For example, Supergreen Tonik contains 100% of the daily value for vitamin C, vitamin D, thiamin, riboflavin, niacin, vitamin B6, vitamin B12, biotin, pantothenic acid, and zinc.
They also provide full transparency of their ingredients. If you still aren’t sure, their consumer reviews say it all.
Vitamin D Dosage Recommendation
Because vitamin D is a fat-soluble vitamin, it is not recommended to consume high amounts as it becomes stored in our fat cells and can lead to toxicity.
The current recommended amount of vitamin D for those between 1-70 years old is 600 international units (IUs). (Source)
To avoid toxicity, the Food and Drug Administration created a tolerable upper intake level (UL) for vitamin D.
This is the maximum daily amount of vitamin D that will not likely result in any harmful effects. The UL for vitamin D for those 9 years and older is 4,000 IU. (Source)
Reading Supplement Labels
Before starting a vitamin D supplement, you must know how to read supplement labels.
Just like food, supplements are required to label the supplement facts and ingredients. This provides you with information on the dose and serving size of ingredients along with what is included in the supplement itself.
When looking for a high-quality supplement, it pays to choose one that provides third-party testing for quality.
Companies might show that they have third-party testing by including a certification from certain organizations such as the United States Pharmacopeia, ConsumerLab, or NSW International. These certifications often include a seal that is printed on the supplement label.
Some supplements, such as green powders, might include proprietary blends in their ingredients list. A proprietary blend is a unique set of ingredients created by the manufacturer for a specific purpose.
For example, Supergreen Tonik contains a proprietary greens blend that includes organic spirulina, collard leaf, spinach leaf, barley grass, chlorella, and horseradish tree leaf powder. They also have a proprietary nootropic and immunity blend.
Many supplement companies do not disclose their proprietary blend ingredients.
This can be harmful to consumers as they are not aware of what they are taking. Some ingredients may interact with medications or other supplements being taken.
This is why it is recommended to always choose your supplements from reputable manufacturers preferably who provide third-party testing and full transparency of their ingredients.
Vitamin D is an essential vitamin for our bone and immune health. Unfortunately, many of us are probably not getting enough.
If you are concerned about your vitamin D levels, consider getting them tested.
You can increase your vitamin D by getting more sun exposure, increasing your intake of vitamin D-rich foods, or taking a vitamin D supplement.
Whether you choose to take a vitamin D2 or vitamin D3 supplement in the form of a multivitamin or green powder, always choose brands that you trust that provide transparency of their product because your health is the most important thing to consider when choosing what to put in your body.
Meghan is a Registered Dietitian/Nutritionist from San Jose, California. She received her undergraduate degree from San Diego State University in 2015. Following an unexpected cross-country trip that landed her in Florida, she completed her didactic training through AdventHealth Orlando.
Meghan has extensive experience in multiple aspects of dietetics including critical care, motivational interviewing, writing, and research. She is passionate about health and wellness and has dedicated her free time to breaking down complicated nutrition topics and disseminating them to the public through the arena of writing.