Vitamin D is a nutrient that helps maintain overall health. Despite its name, it acts like a hormone, affecting bone health, immune function, and even mood. In our modern lifestyle, where staying indoors is becoming more common, understanding vitamin D is crucial.
Vitamin D is commonly called the sunshine vitamin. Because we know that it can be obtained from the sunlight by exposing the body. It can also be obtained from foods. It plays important roles in many bodily functions. Its importance goes beyond bone health, affecting immune response, muscle function, and even mood regulation.
It is a fat-soluble vitamin so the body can store it for long periods of time. It is present in two main forms, D2 (ergocalciferol) and D3 (cholecalciferol).
Vitamin D2 vs D3
Both vitamin D2 and D3 are inactive forms that help the body absorb calcium and phosphorus. Their molecular structures are slightly different. Yet they differ in sources, efficacy, and metabolism. Below is an in-depth look at supplements and their differences and implications for health.
Chemical Differences and Sources
| Vitamin D2 | Vitamin D3 | |
| Sources | Plants-based foods include fruits and vegetables | Animals-based foods, like oily fish, liver, and eggs, etc. |
| How it’s produced | It can be made from plants and produced artificially. | It is produced in the human body after exposure to the sun. |
| Other names | Ergocalciferol | Cholecalciferol |
Efficacy and strength
Efficacy in increasing vitamin D levels:
Studies consistently indicate that vitamin D3 is more potent and effective in increasing serum 25-hydroxyvitamin D concentrations than D2. Research shows that even when used in equal amounts. D3 maintains higher and more stable blood levels over time.
Process duration:
Due to differences in binding affinity and metabolism, D3 has a longer half-life. Meaning its effects persist in the bloodstream for longer. This prolonged effect is especially important for maintaining adequate vitamin D levels during periods of low sun exposure.
Metabolism and bioavailability
Metabolic pathways:
Both forms D2 and D3 undergo hydroxylation in the liver to form 25-hydroxyvitamin D. Which is the main form measured to assess vitamin D status. Then they are converted to their active form (1,25-dihydroxyvitamin D) in the kidneys.
However, the metabolic pathway of D3 is generally more efficient. Which contributes to its higher bioavailability.
Bioavailability:
The high bioavailability of vitamin D3 is due to its strong binding to vitamin D binding protein. Which increases its absorption and utilization in the body. This makes D3 the preferred choice for supplementation in many medical settings.
Supplementation and Health Implications
Supplementation Recommendations:
Supplementation is very important for people with vitamin D deficiency or limited sun exposure. Clinical guidelines often support vitamin D3 supplementation because of its increased potency and long-lasting effects.
For example, doses are typically developed based on age, geographic location, and overall health. Many experts recommend D3 as a primary option.
Health Outcomes:
Maintaining optimal vitamin D levels helps support bone health, reducing the risk of fractures and osteoporosis. Additionally, adequate intake is associated with improved immune function, mood regulation, and potential protection against certain chronic diseases.
The consensus among healthcare professionals is that both D2 and D3 can improve vitamin D levels. D3 is generally more effective in long-term management.
Summary:
In summary, both vitamin D2 and D3 help improve vitamin D status. D3 stands out as a more potent, bioavailable, and long-lasting option. This makes it a preferred choice for supplementation in many scenarios, especially for those at risk of deficiency.
Understanding these differences helps you make informed decisions about dietary supplements and overall health management.
What does taking vitamin D do for you
Vitamin D exists in forms or types. Both forms remain inactive until the body processes it. They play the following roles in the body:
- Regulating metabolism of calcium and phosphorus.
- Supporting bone health.
- Fighting off disease, causing organisms like viruses and bacteria.
- Supporting the immune system.
- Strengthen muscles.
- Regulating and functioning of the nervous system.
Some studies suggest that vitamin D3 may be better than vitamin D2 at increasing vitamin D levels. However, more research is needed to determine how the two types affect different groups of people.
How much vitamin D each day?
It is very important to get the right amount of vitamin D. Too little can cause deficiency, while too much can cause negative effects. The recommended dietary allowances (RDA) are the following:
| Demographics | RDA (mcg/IU) |
| Infants (0-12 months) | 10 mcg (400 IU) |
| Children and teenagers (1-18 years) | 15 mcg (600 IU) |
| Adults ages 18–70 years | 15 mcg (600 IU) |
| Adults age 70+ years | 20 mcg (800 IU) |
| Pregnant or breastfeeding | 15 mcg (600 IU) |
If you are vegetarian, you can take supplements containing vitamin D2. If you eat animal-based food products, you can buy supplements that contain vitamin D3.
What foods have high levels of vitamin D?
The foods that have high levels of vitamin D are the following:
- Fish oils such as cod liver oil is a popular supplement that is high in vitamin A and D.
- Fortified foods such as breakfast cereals, plant milks, like almond and rice milk, fat spreads.
- Animal-based foods such as Egg, yolks, Red, meat, Liver, Cheese, etc.
- You can also increase your vitamin D levels by exposing yourself to the sunlight and spending some time.
Note: Cod liver oil is high in vitamin A, which can be harmful and toxic in high doses. Be careful when taking fish oil supplements and must consult with specialists.
What can low vitamin D do to your body?
Low levels of vitamin D can cause bone pain, muscle weakness, and an increased risk of fractures. It can also lead to anemia and respiratory tract infections from deficiency.
Symptoms:
- Bone pain, fractures, muscle pain, and weakness
- Increased risk of falls in older adults
- Anemia
- Respiratory tract infections such as the common cold, bronchitis, and pneumonia
- Viral diseases, such as hepatitis and the flu
What can cause vitamin D to be low?
Vitamin D deficiency can be caused by several possible causes such as:
- A lack of sunlight exposure is a common cause of deficiency.
- Not eating foods rich in vitamin D, or not absorbing enough from food, can cause deficiency.
- It may also be caused by geographical factors. If you live in countries such as Northern Canada, Alaska, etc. There may be less access to the sun’s UVB rays, especially in winter.
- The ability of converting inactive forms of vitamin D to active forms may decrease with age. As a result, calcium absorption will decrease.
- In our modern lifestyle, staying indoors is becoming more common. Then people have less opportunity to expose their skin to sunlight and may have deficiency.
- Pregnant women may have deficiency. Due to some reasons experts are not assured whether supplements are a good idea.
- Human milk is deficient in D vitamin, which means that breastfed babies are at risk of deficiency. Vitamin D status of breastfeeding mothers and infants in the global human milk study. To learn more visit the study report on MDPI.
What is the best way to get vitamin D naturally?
If you have a deficiency, not a big deal. You can get vitamin D to increase levels from different sources naturally. The natural ways to treatment are the following:
- Get moderate exposure to the sunlight.
- Eat a variety of vitamin D-rich foods
- If you have any health issue or any other reason for deficiency. You can take supplements suggested by specialists.
What will happen if you take too much vitamin D?
Vitamin D is a fat-soluble vitamin so it should be obtained in adequate amounts. In case, if you take too much vitamin D you may have certain health issues because of its side effects.
- Excess intake increases calcium levels in the blood, causing symptoms such as nausea, vomiting, constipation, and abdominal pain.
- High levels of calcium can cause kidney stones or even kidney failure, as well as damage the kidneys over time.
- Neurological and muscular symptoms such as muscle weakness, fatigue, confusion, dizziness, and irritability.
- Long-term supplementation can upset the calcium balance in your body, potentially weakening bones.
Conclusion:
Vitamin D, the “sunshine vitamin,” is beneficial for bone health, immune system, and mood regulation. It acts like a hormone with D3 (cholecalciferol). Which is obtained from sunlight, fatty fish and eggs, outperforming D2 (ergocalciferol) in strength and longevity. While both forms increase calcium absorption.
Studies show that D3 is more effective at maintaining healthy blood levels, making it a better choice for supplementation. Modern indoor lifestyles and limited sun exposure increase the risks of deficiency. The deficiency risks include bone pain, weakened immunity, and fatigue. Combat this with 10-30 minutes of sunlight daily, a diet rich in vitamin D, or supplements designed for non-vegans and vegetarians.
However, balance is key: too much vitamin D can cause toxicity, leading to kidney problems or calcium imbalances. Prefer safe sun exposure and consult a healthcare provider to improve your levels. Vitamin D is a small nutrient with huge health benefits.
