Vitamin D is not just one vitamin but a family that exists in multiple forms. They all share a similar chemical structure but have specific functions too.

Amongst dietary sources, two nutrients of vitamin D are most prominent, D2 and D3. Both forms contribute to the blood levels of vitamin D but differ in certain functions.

According to recent studies, vitamin D3 is better at increasing the vitamin D content in the body than D2. This article will discuss the notable differences between them.

Vitamin D

Vitamins are divided into two types, depending upon whether they are soluble in water or fat. Vitamin D is soluble in fat and has varied functions like regulating calcium and phosphorus, building immunity, and improving bone health.

When exposed to the sun, our body makes vitamin D. But residing in areas with less sunshine or leading a relatively indoor lifestyle can stunt this natural process, leading to deficient levels.

Vitamin D is present in a few food ingredients, although only select ones contain a significant amount. It is tough to ingest the required amount solely through your diet.

Regular-use pantry items like bread, dairy products, and fruit juices are fortified with vitamin D to combat the deficiency.

Since vitamin D is a vitamin that dissolves in fat, it is better to pair vitamin D food sources with fat or opt for fat-based supplements.

Forms Of Vitamin D

Vitamin D prominently exists in two forms:

• Ergocalciferol or D2
• Cholecalciferol or D3

Sources Of Vitamin D2 And D3

Vitamin D3 is solely found in animal-based foods, whereas D2 is a plant-based form of vitamin D and exists in fortified goods too.

D3 is available in ingredients like fish, butter, eggs, and animal liver. D2 comes in the ultraviolet (UV) - exposed mushrooms, fortified items, and supplements.

Vitamin D2 is mainly used to fortify regular-use pantry items due to its cost-effectiveness.

Sunlight Produced Vitamin D3

Out of both nutrients, vitamin D3 is the one that our body produces upon exposure to sunlight.

Ultraviolet B (UVB) rays in specific initiate the formation of vitamin D3 from dehydrocholesterol. Mushrooms also create vitamin D2 in a similar pattern, with the help of ergosterol, the fatty molecules in plant oil.

This property of self-synthesis of vitamin D creates a possibility to attain enough vitamin D solely through sunlight. If you are an Indian, you require around thirty minutes of midday sunlight twice a week. It may not apply to other countries, especially countries farther away from the equator. Individuals living in such areas may require more time under the sun.

Sunscreen helps in preventing harmful rays that have cancerous characteristics. You can take precautions and not spend too much time under the sun.

Toxicity from vitamin D3 procured from the sun can never happen as our body personally regulates this and will create less or more accordingly. If you consume a high amount of vitamin D in your diet, it can lead to overdose.

Most people do not acquire enough vitamin D from the sun due to a rise in a sedentary lifestyle. We must give importance to spending some outdoor time and consuming nutritious vitamin D-rich foods.

Is Vitamin D3 Superior to D2?

Although both contribute to increasing the vitamin D content within the body, how they metabolize varies. They are absorbed in the blood similarly but get processed differently in the liver.

D2 converts to 25-hydroxyvitamin D2, and D3 transforms into 25-hydroxyvitamin D3. Both of them together are called calcifediol as a unit.

The calcifediol amount circulating throughout the body determines the levels of stocked-up vitamin D. Biochemical tests measure this nutrient specifically to check for adequate levels.

Compared to vitamin D3, D2 produces less calcifediol, with some evidence pointing out that vitamin D3 may be more effective at increasing blood levels of vitamin D than D2.

A group of 32 women was tested with D3 and D2, resulting in a better turnout of vitamin D levels with D3. It was two times more effective than D2.

Both forms exist in supplements and are effective treatments for deficient vitamin D levels.

Are D2 Supplements Lower In Quality?

Experts believe vitamin D2 may be of lower quality than vitamin D3. It may be because D2 degrades at a faster rate than D3. It appears to be more affected by external conditions like heat, moisture, and climate. It has led experts to believe that supplements with D2 go rancid quickly.

There have not been any tests for the effect of degraded supplements on human health yet. No comparative studies have been done to test the stability of both vitamins, either.

This area requires more research, but it is better to store your vitamins in a secure and dry place away from heat and moisture.

Improving Your Vitamin D Levels

Since there are multiple ways to obtain vitamin D, individuals can choose their preferred way of acquiring it.

• Sunlight exposure for a minimum of 30 minutes per day
• Consuming fortified foods
• Opting for vitamin-rich ingredients like fish, eggs, and UV-treated mushrooms
• Taking supplements

If you rely on supplementation, take precautions and don't exceed the maximum threshold of 4,000 IU daily.

The recommended range for ingestion is 400-800 IU, and supplements may contain up to 1,000 to 2,000 IU. Consult your physician for the appropriate dosage required by you.

Conclusion

Vitamin D comes in multiple forms, prominently, D2 (a plant-based source) and D3 (an animal-based source). Evidence shows that D3 may be better at helping one achieve higher levels than D2, though it requires further research. To get adequate vitamin D levels, ingest more vitamin D-rich foods, add more outdoor time in the sunlight, or opt for vitamin D supplements per an expert's guidance.