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Everything You Need to Know About Vitamin D: Benefits, Foods & Dosage

What is Vitamin D?

Vitamin D is often called the ‘sunshine vitamin’ because our bodies can produce it when our skin is exposed to sunlight. This essential nutrient plays such an important role in our overall health, particularly in bone strength and calcium absorption.

Back in the Industrial Revolution, children suffered from a condition called rickets, where their bones didn’t form properly. Scientists discovered that rickets could be prevented and cured by ensuring enough Vitamin D in the diet or through sunlight exposure.

To start, what are 5 facts about vitamin D?

1. It’s Fat-Soluble: Vitamin D is stored in your body’s fat, which means it can be used later, unlike water-soluble vitamins that get flushed out.
2. Two Types of Vitamin D: Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol). Vitamin D3 is the more potent form and is what your body naturally produces when exposed to sunlight.
3. Vitamin D Helps Absorb Calcium: It’s essential for maintaining healthy bones and teeth because it helps your body absorb calcium.
4. Vitamin D Deficiency Is Linked to Serious Health Issues: This includes osteoporosis, cognitive decline and weakened immune function.
5. You Can’t Get Enough from Food Alone: Most people need sunlight or supplements and a vitamin D-rich diet to maintain healthy levels.

Now that all that information is in your brain, let’s learn all about vitamin D. Jump there now:

• How Vitamin D Is Made and Used by the Body
• What Exactly Does Vitamin D Do?
• Sources of Vitamin D
• How Much Vitamin D Do You Need?
• What Are the Signs You Need Vitamin D?
• Who Is at Risk of Vitamin D Deficiency?
• Can You Get Too Much Vitamin D?
• Quick Tips to Boost Your Vitamin D Levels

How Vitamin D Is Made and Used by the Body

The process of making Vitamin D starts in our skin. When we’re exposed to sunlight, specifically ultraviolet B (UVB) rays, our skin converts a compound into Vitamin D. This vitamin then goes through further processes in the liver and kidneys to become active and ready to work in the body. You can also get Vitamin D from certain foods, like fatty fish, egg yolks and fortified products, or through supplements if needed.

Once in its active form, Vitamin D not only helps with calcium absorption but also plays a role in maintaining a healthy immune system and supporting muscle function. This makes it an essential vitamin for overall well-being, beyond just its role in bone health.

What Exactly Does Vitamin D Do?

Vitamin D plays an important role in several body functions, most notably in calcium absorption, which is needed for maintaining healthy bones and teeth. Without enough vitamin D, the body struggles to absorb calcium from food, and over time, this can lead to weakened bones and conditions like osteoporosis. But vitamin D benefits go far beyond bones. It also supports your:

1. Immune System: Vitamin D helps to activate the immune system, which makes it easier for your body to fight infections. Research suggests that those with adequate vitamin D levels are less likely to develop infections like the flu and cold. Recent studies have even linked lower vitamin D levels to more severe outcomes in COVID-19.
2. Muscle Function: Adequate vitamin D levels are vital for muscle health, which is why muscle weakness is a common sign of deficiency. Studies have shown that vitamin D can help reduce the risk of falls in older adults by improving muscle strength.
3. Brain Health: Studies also suggest that vitamin D may have an effect on cognitive health. Low vitamin D levels have been associated with cognitive decline and diseases like dementia and Alzheimer’s disease. One study found that low vitamin D levels might increase the risk of Alzheimer’s.
4. Cancer Prevention: Research on vitamin D’s effect on cancer is ongoing. Some studies suggest that adequate vitamin D levels may help lower the risk of certain cancers, though more studies are needed.

Further Reading: Supplements to Boost Your Immune System

Sources of Vitamin D

1. Sunlight

The sun is the most natural source of vitamin D. Spending about 10-30 minutes outside a few times a week, with your face, arms, or legs exposed, can help. Remember, though, that factors like skin tone, age, sunscreen and even window glass can affect how much vitamin D your body makes.

2. Food

Few foods naturally contain vitamin D, but some are fortified to help you meet your needs. So, what food is highest in vitamin D? These would be fatty fish and fish liver oils, but some vitamin D foods include:

• Fatty fish: Salmon (570 IU per 3 ounces), mackerel (360 IU per 3 ounces), sardines (193 IU per 3 ounces), trout (645 IU per 3 ounces)
• Cod liver oil: 1,360 IU per tablespoon
• Egg yolks: 44 IU per yolk
• Mushrooms: UV-treated varieties can provide up to 450 IU per 100 grams
• Fortified foods: Milk (120 IU per cup), plant-based alternatives like soy or almond milk (100-140 IU per cup), orange juice (100 IU per cup), and cereals (40-100 IU per serving)
• Cheese: Certain varieties, like cheddar, contain about 12 IU per ounce
• Beef liver: 42 IU per 3 ounces

For high levels of vitamin D, vitamin D vegetables only include mushrooms, while there are no vitamin D fruits with high levels of the vitamin other than fortified orange juice.

Further Reading: List of Vitamins and Minerals

3. Supplements

If you’re not getting enough from sunlight or food, supplements can fill the gap. There are two types:

• D2 (ergocalciferol): Found in mushrooms exposed to UV light and fortified foods like plant-based milk, cereal and orange juice.
• D3 (cholecalciferol): Found in fatty fish (e.g., salmon, mackerel), egg yolks, liver, and butter. Your skin also makes D3 when exposed to sunlight. 

Note: Vitamin D vs D3: Vitamin D is the nutrient that helps your body absorb calcium and phosphorus to keep bones strong and support overall health. It exists in two main forms D2 and D3.D3 is more effective at raising and maintaining vitamin D levels in the body. Studies show D3 produces higher levels of calcifediol (the form of vitamin D measured in blood) compared to D2. D3 is superior because it is better absorbed and stored in the body, it is more effective in improving vitamin D levels as it aligns with how the body naturally produces vitamin D. D2 is often used in fortified foods because it’s cheaper to produce, but it’s not as effective.

How Much Vitamin D Do You Need?

Here’s a quick guide to the Recommended Dietary Allowances (RDAs) to help you figure out what vitamin D dosage you need each day:

• Babies (0–12 months): 10 mcg (400 IU)
• Children & Adults (1–70 years): 15 mcg (600 IU)
• Older Adults (>70 years): 20 mcg (800 IU)

How Much Vitamin D3 Should I Take Daily?

For most adults, the recommended daily dose is 600–800 IU, but if you have a deficiency, your doctor may suggest a higher dose. It’s important not to exceed the maximum daily dose of vitamin D, which is 4,000 IU per day, without a doctor’s recommendation, as it can lead to hypercalcemia (high calcium levels), causing nausea, vomiting and other vitamin D side effects like weakness and fatigue, kidney damage and heart rhythm problems.

What Are the Signs You Need Vitamin D?

If you suspect you're not getting enough vitamin D, here are some signs of vitamin D deficiency to look out for:

• Bone pain or tenderness
• Muscle weakness or cramps
• Fatigue or depression
• Frequent infections
• Hair loss: Some studies suggest a link between vitamin D deficiency and hair loss, particularly in women.

Further Reading: Guide to Healthy Bones

Who Is at Risk of Vitamin D Deficiency?

Certain groups of people are more likely to experience vitamin D deficiency. Factors that put you at risk include:

• Dark skin: People with naturally darker skin have higher amounts of melanin, which blocks UV radiation, making it harder for the skin to produce vitamin D.
• Limited sun exposure: Those who work night shifts, live in regions with little sunlight, or stay indoors for long periods are at higher risk. Studies suggest that people in northern latitudes, where sunlight exposure is minimal in the winter months, are particularly vulnerable.
• Obesity: Too much body fat can isolate vitamin D, making it less available to the body. A study highlighted the link between higher body fat and lower circulating vitamin D levels.
• Certain health conditions: Diseases like chronic kidney disease, liver disease, and inflammatory bowel disease (e.g., Crohn’s disease) can interfere with vitamin D metabolism. People with these conditions often require supplements to maintain adequate levels of the vitamin.
• Age: As you age, your skin’s ability to produce vitamin D diminishes. Older adults also often spend more time indoors and may have less efficient absorption of vitamin D.

Can You Get Too Much Vitamin D?

Yes, although it’s rare. Overloading on vitamin D (usually through supplements) can lead to nausea, kidney problems or calcium buildup in the blood, which is harmful. Stick to recommended doses unless directed by your doctor.

Quick Tips to Boost Your Vitamin D Levels

1. Soak Up the Sun: Enjoy safe sun exposure, but don’t forget your sunscreen for extended time outdoors.
2. Eat Smart: Incorporate vitamin D-rich foods into your diet.
3. Supplement Wisely: If your vitamin D is low, your doctor may recommend you take a vitamin D supplement. Choose a trusted brand and stick to the recommended dose.
4. Check Your Levels: A simple blood test can tell if you’re low on vitamin D.

End Note

Vitamin D plays an important role in supporting many bodily functions, including bone health, immune function, and muscle strength. Making sure you get enough vitamin D through sunlight, diet or supplementation can help prevent a range of health issues.

If you're concerned about your vitamin D levels, speak with your doctor about getting a blood test and appropriate treatment, such as vitamin D tablets. With the right approach, you can maintain healthy vitamin D levels and enjoy the many benefits this essential nutrient provides!

If you’re looking to boost vitamin D’s benefits on the immune system, you can also try Magnesium Glycinate 500mg as well as BCM 95® Turmeric Curcumin!