Vitamin D Levels by Country: Deficiency Rates and Food Sources 2026

Vitamin D deficiency is often called a "silent epidemic." Unlike scurvy or rickets in their most visible forms, low vitamin D status develops gradually and can persist for years before producing noticeable symptoms. Yet the consequences are far from silent: weakened bones, impaired immunity, chronic fatigue, and a growing body of evidence linking insufficiency to cardiovascular disease, depression, and certain cancers.

According to a 2022 meta-analysis published in The Lancet Global Health, roughly 40 percent of the global population has serum 25-hydroxyvitamin D (25(OH)D) concentrations below the widely accepted sufficiency threshold of 50 nmol/L. In some regions, that figure exceeds 70 percent. The problem spans every continent, every age group, and every income level.

This post compiles the most current country-level data, ranks the best dietary sources of vitamin D, and outlines evidence-based strategies for improving your status, whether you live at the equator or above the Arctic Circle.

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Quick Summary

Vitamin D deficiency affects roughly 1 billion people globally. Northern European and Middle Eastern countries often report the highest rates, driven by limited sun exposure and cultural factors. The richest dietary sources are fatty fish, cod liver oil, and fortified foods. Daily requirements range from 400 IU for infants to 1500-2000 IU for adults at risk. Tracking your vitamin D intake alongside other micronutrients is one of the most practical steps you can take.

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What Counts as Vitamin D Deficiency?

Before diving into the data, it is important to understand the thresholds used throughout this article. Serum 25(OH)D is the standard biomarker:

Status	Serum 25(OH)D Level
Severely deficient	< 25 nmol/L (< 10 ng/mL)
Deficient	< 50 nmol/L (< 20 ng/mL)
Insufficient	50-75 nmol/L (20-30 ng/mL)
Sufficient	75-150 nmol/L (30-60 ng/mL)
Upper safe range	150-250 nmol/L (60-100 ng/mL)

These thresholds are based on guidelines from the Institute of Medicine (IOM) and the Endocrine Society, though there is ongoing debate about whether the "sufficient" cutoff should be 50 or 75 nmol/L.

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Vitamin D Deficiency Rates by Country

The following table compiles data from national health surveys, the EPIC cohort study, NHANES (United States), and peer-reviewed publications from 2018 to 2025. Where national surveys are unavailable, large regional studies are used.

Europe

Country	Avg. Serum 25(OH)D (nmol/L)	% Deficient (<50 nmol/L)	% Severely Deficient (<25 nmol/L)	Fortification Policy
Finland	75	15%	2%	Mandatory (milk, spreads)
Sweden	73	18%	3%	Voluntary (dairy, spreads)
Norway	65	22%	4%	Voluntary (dairy, cod liver oil culture)
Iceland	57	28%	5%	Voluntary (dairy)
Denmark	56	30%	6%	Voluntary (margarine)
Ireland	56	29%	7%	Voluntary (milk, cereals)
Netherlands	54	33%	8%	Voluntary (margarine)
United Kingdom	47	40%	12%	Voluntary (cereals, spreads)
Germany	46	42%	12%	None mandatory
Belgium	45	45%	14%	None mandatory
France	43	48%	15%	None mandatory
Switzerland	46	41%	11%	Voluntary (dairy)
Austria	44	44%	13%	None mandatory
Poland	42	50%	16%	None mandatory
Spain	45	40%	12%	None mandatory
Italy	44	46%	14%	None mandatory
Greece	43	47%	15%	None mandatory
Turkey	35	62%	25%	Voluntary (limited)
Romania	40	52%	18%	None mandatory
Czech Republic	44	45%	14%	None mandatory

Middle East and North Africa

Country	Avg. Serum 25(OH)D (nmol/L)	% Deficient (<50 nmol/L)	% Severely Deficient (<25 nmol/L)	Fortification Policy
Saudi Arabia	28	75%	40%	Voluntary (limited)
UAE	30	72%	35%	Voluntary (dairy, flour)
Iran	32	68%	30%	None mandatory
Jordan	30	70%	33%	Voluntary (flour, oil)
Egypt	35	60%	25%	None mandatory
Morocco	38	55%	20%	Voluntary (oil)
Tunisia	37	56%	22%	None mandatory
Lebanon	33	65%	28%	None mandatory

Americas

Country	Avg. Serum 25(OH)D (nmol/L)	% Deficient (<50 nmol/L)	% Severely Deficient (<25 nmol/L)	Fortification Policy
United States	60	28%	6%	Mandatory (milk); voluntary (OJ, cereals)
Canada	63	25%	5%	Mandatory (milk, margarine)
Mexico	48	38%	12%	Voluntary (milk)
Brazil	52	34%	10%	None mandatory
Argentina	45	44%	15%	Voluntary (dairy)
Chile	42	48%	16%	Voluntary (milk)
Colombia	50	36%	11%	None mandatory

Asia-Pacific

Country	Avg. Serum 25(OH)D (nmol/L)	% Deficient (<50 nmol/L)	% Severely Deficient (<25 nmol/L)	Fortification Policy
India	30	70%	30%	None mandatory
China	40	50%	18%	None mandatory
Japan	50	35%	10%	None mandatory
South Korea	44	47%	14%	None mandatory
Australia	63	23%	5%	Voluntary (margarine, some dairy)
New Zealand	60	27%	6%	Voluntary (margarine)
Thailand	48	40%	14%	None mandatory
Indonesia	45	46%	17%	None mandatory
Pakistan	28	73%	38%	None mandatory
Bangladesh	32	65%	28%	None mandatory

Africa

Country	Avg. Serum 25(OH)D (nmol/L)	% Deficient (<50 nmol/L)	% Severely Deficient (<25 nmol/L)	Fortification Policy
South Africa	55	30%	8%	Voluntary (margarine)
Nigeria	50	35%	10%	None mandatory
Kenya	58	26%	7%	Voluntary (edible oils)
Ethiopia	46	42%	14%	None mandatory

Key takeaways from the data:

• Countries with mandatory fortification (Finland, Canada, United States) consistently show lower deficiency rates, even at high latitudes.
• Middle Eastern countries report some of the highest deficiency rates globally, despite abundant sunshine. Conservative dress, extreme heat discouraging outdoor activity, and limited fortification all contribute.
• South Asia (India, Pakistan, Bangladesh) faces widespread deficiency driven by a combination of darker skin pigmentation, vegetarian diets, urbanization, and pollution reducing UV exposure.

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Top Vitamin D Food Sources Ranked

Diet alone rarely provides enough vitamin D to prevent deficiency for most people, but it remains a critical piece of the puzzle. The following table ranks foods by vitamin D content per 100 grams and per typical serving size.

Food	IU per 100g	Typical Serving	IU per Serving	% Daily Value per Serving*
Cod liver oil	10,000	1 tsp (5 mL)	450	56%
Wild sockeye salmon	860	85g (3 oz)	730	91%
Farmed Atlantic salmon	525	85g (3 oz)	445	56%
Smoked salmon	685	85g (3 oz)	580	73%
Canned sardines (in oil)	480	85g (3 oz)	408	51%
Rainbow trout (farmed)	635	85g (3 oz)	540	68%
Herring (Atlantic)	680	85g (3 oz)	578	72%
Mackerel (Atlantic)	640	85g (3 oz)	544	68%
Canned tuna (light, in water)	268	85g (3 oz)	228	29%
Swordfish	560	85g (3 oz)	476	60%
Maitake mushrooms (raw)	1,123	50g (1 cup diced)	562	70%
UV-exposed white mushrooms	1,046	50g (1 cup sliced)	523	65%
Egg yolk	218	1 large yolk (17g)	37	5%
Fortified whole milk	52	240 mL (1 cup)	125	16%
Fortified orange juice	42	240 mL (1 cup)	100	13%
Fortified cereal (typical)	40-100	30g (1 cup)	40-100	5-13%
Beef liver	42	85g (3 oz)	36	5%
Cheddar cheese	24	28g (1 oz)	7	1%

*Based on an 800 IU Daily Value (DV) as used on current nutrition labels.

Important notes:

• Wild-caught salmon contains significantly more vitamin D than farmed salmon. A 2009 study in the Journal of Clinical Endocrinology & Metabolism found wild salmon averaged 988 IU per 3.5 oz serving versus 240 IU for farmed.
• Mushrooms exposed to UV light are the only significant plant-based source. Look for "UV-treated" or "high vitamin D" labels.
• Egg yolks from pasture-raised hens can contain 3-4 times more vitamin D than conventional eggs.

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Vitamin D in Fortified Foods: A Country Comparison

Fortification policies vary dramatically and directly impact population-level vitamin D status.

Country	Fortified Food	Typical Amount Added
United States	Milk (cow's)	100 IU per 240 mL cup
United States	Orange juice (select brands)	100 IU per 240 mL cup
United States	Breakfast cereals	40-100 IU per serving
Canada	Milk (cow's)	100 IU per 240 mL cup
Canada	Margarine	53 IU per 10g serving
Finland	Fluid milk	40 IU per 100 mL
Finland	Fat spreads	80 IU per 100g
Sweden	Milk (low-fat)	38 IU per 100 mL
Sweden	Spreads/margarine	300 IU per 100g
United Kingdom	Margarine/spreads	Variable (voluntary)
India	Fortified edible oil (pilot)	280 IU per 15 mL
Australia	Margarine	40-120 IU per 100g
Jordan	Bread flour	20 IU per 100g

Finland's aggressive fortification program, introduced in 2003 and expanded in 2010, is widely cited as a public health success. Mean serum 25(OH)D levels in the Finnish population rose from approximately 48 nmol/L in 2000 to 75 nmol/L by 2020, according to data published in the British Journal of Nutrition.

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Key Risk Factors for Vitamin D Deficiency

1. Latitude and Sun Exposure

At latitudes above 35 degrees N or below 35 degrees S, UVB radiation is insufficient for skin synthesis of vitamin D during winter months. In cities like London (51 degrees N), Stockholm (59 degrees N), or Anchorage (61 degrees N), virtually no cutaneous vitamin D production occurs from October through March.

2. Skin Pigmentation

Melanin acts as a natural sunscreen. Individuals with darker skin require 3 to 5 times more sun exposure to produce the same amount of vitamin D as those with lighter skin. NHANES data consistently shows that Black Americans have mean serum 25(OH)D levels approximately 40 percent lower than white Americans.

3. Age

The skin's capacity to synthesize vitamin D declines with age. A 70-year-old produces roughly 25 percent of the vitamin D that a 20-year-old would under identical sun exposure. This is compounded by reduced outdoor activity and lower dietary intake in older adults.

4. Obesity

Vitamin D is fat-soluble and becomes sequestered in adipose tissue. Studies consistently report that individuals with a BMI above 30 have serum 25(OH)D levels that are 20 to 30 percent lower than normal-weight individuals, even with equivalent intake and sun exposure.

5. Indoor Lifestyle and Urbanization

Modern life increasingly happens indoors. Office workers, students, and remote employees can go entire days without meaningful sun exposure. Air pollution in dense cities like Delhi, Beijing, and Cairo further reduces the UVB radiation that reaches the skin.

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Recommended Daily Intake: IOM vs. Endocrine Society

Two influential guidelines exist, and they differ significantly.

Age Group	IOM Recommended Dietary Allowance (RDA)	Endocrine Society Recommendation
Infants (0-12 months)	400 IU (10 mcg)	400-1,000 IU
Children (1-18 years)	600 IU (15 mcg)	600-1,000 IU
Adults (19-70 years)	600 IU (15 mcg)	1,500-2,000 IU
Older adults (71+ years)	800 IU (20 mcg)	1,500-2,000 IU
Pregnant/lactating women	600 IU (15 mcg)	1,500-2,000 IU

The IOM guidelines are designed for generally healthy populations, while the Endocrine Society's higher recommendations target individuals at risk of deficiency. Many researchers and clinicians now lean toward the higher range, especially for people living at northern latitudes or with limited sun exposure.

The tolerable upper intake level (UL) set by the IOM is 4,000 IU per day for adults. Toxicity is rare and typically associated with prolonged intake above 10,000 IU per day.

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Vitamin D2 vs. D3: Does the Form Matter?

Vitamin D exists in two main forms:

• Vitamin D2 (ergocalciferol): Derived from fungi and yeast exposed to UV light. Found in UV-treated mushrooms and some supplements.
• Vitamin D3 (cholecalciferol): Produced in human skin upon UVB exposure. Found in animal-based foods (fatty fish, egg yolks, liver) and lichen-derived supplements.

Does it matter which you take?

Yes. A 2012 meta-analysis in the American Journal of Clinical Nutrition found that vitamin D3 is approximately 87 percent more potent than D2 in raising and maintaining serum 25(OH)D levels. D3 also has a longer shelf life and greater stability. For these reasons, most clinical guidelines now recommend D3 for supplementation. Vegans can opt for lichen-derived D3 supplements.

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Seasonal Variation in Vitamin D Levels

Vitamin D status follows predictable seasonal patterns, particularly at higher latitudes.

Season	Typical Serum Change (nmol/L)	Notes
Late summer (Aug-Sep)	Peak levels (+15 to +25 above annual mean)	Maximum UVB exposure
Autumn (Oct-Nov)	Declining (-5 to -10)	Shorter days, lower sun angle
Late winter (Feb-Mar)	Nadir (-15 to -25 below annual mean)	Minimal UVB at high latitudes
Spring (Apr-May)	Recovering (+5 to +10)	Increasing outdoor time

Data from the UK Biobank (n = 449,533) showed that participants measured in winter had a mean serum 25(OH)D of 39 nmol/L compared to 58 nmol/L in summer, a difference of nearly 50 percent. This seasonal swing means that someone who appears "sufficient" in August may be clearly deficient by February without dietary or supplemental adjustment.

Tracking your vitamin D intake becomes especially important during the low-sun months. Tools like Nutrola, which monitors over 100 micronutrients including vitamin D, can help you spot when your dietary intake falls short so you can compensate before your serum levels dip.

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Vitamin D and Health Outcomes: What the Evidence Shows

Bone Health

This is the most well-established benefit. Vitamin D is essential for calcium absorption in the gut. Without adequate vitamin D, only 10 to 15 percent of dietary calcium is absorbed versus 30 to 40 percent with sufficient levels. Chronic deficiency leads to osteomalacia in adults and rickets in children. A 2018 Cochrane review confirmed that vitamin D combined with calcium reduces fracture risk in older adults.

Immune Function

Vitamin D receptors are present on most immune cells. The vitamin modulates both innate and adaptive immunity. A 2017 meta-analysis of 25 randomized controlled trials published in the BMJ found that daily or weekly vitamin D supplementation reduced the risk of acute respiratory tract infections by 12 percent overall, and by 70 percent in individuals who were severely deficient at baseline.

Mood and Mental Health

Observational studies consistently link low vitamin D levels with increased risk of depression. The "D-Vitaal" trial in the Netherlands (2022) found that vitamin D supplementation did not significantly prevent depression in the general older adult population, but subgroup analyses suggested benefit in those with the lowest baseline levels. The relationship appears strongest in individuals who are clearly deficient.

Cardiovascular Health

Large observational studies, including the EPIC cohort, show an association between low vitamin D and increased cardiovascular risk. However, interventional trials such as VITAL (2019) did not find that supplementation reduced major cardiovascular events in vitamin D-replete individuals. The current consensus is that deficiency is a risk marker, and correction of deficiency may be beneficial, but supplementation above sufficiency does not provide additional cardiovascular protection.

Cancer

The VITAL trial found a modest, non-significant reduction in cancer mortality with vitamin D supplementation. Subgroup analyses and subsequent meta-analyses suggest a potential 13 percent reduction in cancer mortality (though not incidence). Research continues, but the evidence is not yet strong enough to recommend vitamin D supplementation specifically for cancer prevention.

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Practical Strategies for Improving Your Vitamin D Status

1. Know Your Baseline

A 25(OH)D blood test is the only way to know your actual status. Request one from your healthcare provider, especially if you have risk factors such as living above 35 degrees latitude, having darker skin, being over 65, or spending most of your time indoors.

2. Optimize Your Diet

While food alone may not fully close the gap, it provides a reliable daily foundation:

• Eat fatty fish 2-3 times per week. Wild salmon, mackerel, sardines, and herring are the most potent natural sources.
• Choose fortified foods. In countries where milk and orange juice are fortified, these contribute meaningfully to daily intake.
• Include UV-exposed mushrooms. They are the best plant-based source and are increasingly available in supermarkets.
• Do not ignore egg yolks. Two pasture-raised eggs per day can contribute 100+ IU.

3. Get Strategic Sun Exposure

For most people, 10 to 30 minutes of midday sun exposure on arms and legs, two to three times per week during summer months, is sufficient to maintain vitamin D production. Darker skin requires more time. Sun exposure should always be balanced against skin cancer risk, and sunscreen should be applied after the initial synthesis window.

4. Supplement Wisely

If you are deficient or at risk, a daily vitamin D3 supplement of 1,000 to 2,000 IU is considered safe and effective for most adults. Those with severe deficiency may need higher loading doses under medical supervision.

5. Track Your Intake

One of the biggest challenges with vitamin D is that people simply do not know how much they are getting from food. Most people overestimate their intake. Using Nutrola to log your meals and review your vitamin D intake over time gives you a clear picture of whether your diet is pulling its weight, or whether supplementation and dietary changes are needed.

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The Bottom Line

Vitamin D deficiency is a global problem with a straightforward set of solutions: strategic sun exposure, a diet rich in fatty fish and fortified foods, targeted supplementation when needed, and consistent monitoring of both intake and serum levels. The country-level data makes one thing clear: even abundant sunshine does not guarantee adequacy, and countries that take a proactive approach through fortification and public health campaigns see measurably better outcomes.

Whether you live in Helsinki or Hyderabad, paying attention to this single nutrient can have outsized effects on your bone health, immune resilience, and overall wellbeing. Start by understanding where your intake stands today, and tools like Nutrola make that easier than ever by tracking vitamin D alongside the other micronutrients that matter most.