Incidence of 16 Vitamin D-associated health conditions has at least doubled since 1999

Diseases doubling since 1999 that track with Vitamin D decline

Summary table

#	Condition	Increase	Period	Demographic	Vitamin D link strength
1	Autism spectrum disorder	~4.8×	2000–2022	Boys; minority children	Strong (OR 5.23)
2	Youth-onset type 2 diabetes	~2×	2001–2018	Black, Indigenous, Hispanic youth	Strong
3	Celiac disease	2.2–2.65×	2000–2019	Children, females	Strong
4	Pediatric IBD	2.33×	2007–2016	Children/adolescents	Strong
5	Adolescent depression (MDE)	2×	2009–2019	Girls, LGBTQ+ youth	Moderate
6	Gestational diabetes	~2×	2003–2016	Asian women, BMI ≥25	Strong
7	Thyroid cancer	~2× (US); >7× (S. Korea)	1999–2013	Young women	Strong (OR 0.76)
8	Kidney cancer (young adults)	2×	2000–2016	Males, Indigenous populations	Strong (OR 0.76)
9	Eosinophilic esophagitis	~21×	2000–2019	Males, White adults	Emerging
10	Sjögren's syndrome	2.09×	2000–2019	Women (9:1)	Documented
11	Graves' disease	2.07×	2000–2019	Women	Documented
12	Pediatric MS	~4.3×	2013–2020	Young women, high latitudes	Very strong
13	Pancreatic cancer (young women)	2.1×	2001–2019	Young women, Black women	Moderate–mixed
14	ADHD (UK girls <18)	4×	2000–2018	Girls and women	Moderate
15	Food-induced anaphylaxis (children)	>3× (UK); >2× (US)	2000–2018	All children, Black children	Moderate (ecological)
16	Rickets resurgence	380% (regional)	2019–2023	Dark-skinned children	Direct causal

At least 17 health conditions have both doubled (or more) since 1999 and carry documented associations with vitamin D deficiency. These span cancers, autoimmune diseases, metabolic disorders, mental health conditions, and allergic diseases — a striking convergence that mirrors a well-documented collapse in population vitamin D status.

Between NHANES III (1988–1994) and NHANES 2001–2004, the share of Americans with 25(OH)D levels

≥30 ng/mL fell from 45% to 23%, and
severe deficiency tripled from 2% to 6%.

While no single condition proves causation, the breadth of this pattern across virtually every organ system warrants serious attention.

The conditions below are organized by evidence strength. Every incidence trend cited uses a baseline year of 1999 or later. Conditions where the best-available doubling data anchors to pre-1999 baselines (e.g., early-onset colorectal cancer, whose doubling traces to a 1987 nadir) are excluded from the main table but noted in footnotes.

The following conditions meet all three criteria with high confidence: a post-1999 baseline, a greater-than-twofold increase in at least one well-defined population, and a vitamin D association supported by meta-analyses or large cohort studies.

1. Autism spectrum disorder

Increase: ~4.8× from 2000 to 2022. CDC's ADDM Network documented prevalence rising from 1 in 150 children (2000) to 1 in 31 (2022). A JAMA Network Open study found a 175% increase in diagnoses across all ages from 2011–2022 alone. Period: 2000 → 2022. Demographics most affected: Boys (3.4:1 male-to-female ratio); Black, Hispanic, and Asian/Pacific Islander children now show the fastest-rising rates. Vitamin D connection: A meta-analysis of 24 case-control studies found children with ASD had mean 25(OH)D levels 7.5 ng/mL lower than controls, with an odds ratio of 5.23 for ASD among vitamin D–deficient children (Wang et al., Nutrients, 2020). Animal models confirm developmental vitamin D deficiency produces autism-relevant behaviors. A Stockholm Youth Cohort study linked neonatal vitamin D insufficiency to 1.75× higher ASD odds (Lee et al., Molecular Psychiatry, 2021). Caveat: Broadened diagnostic criteria (DSM-5 merger of subtypes), improved screening, and better detection in minority communities explain a substantial portion of the increase. Researchers debate how much reflects true prevalence growth versus ascertainment change.

2. Youth-onset type 2 diabetes

Increase: ~2× in prevalence; up to 3× in specific populations. The SEARCH for Diabetes in Youth Study found US prevalence among youth aged 10–19 rose from 0.34 per 1,000 (2001) to 0.67 per 1,000 (2017) — a 95.3% increase. Incidence climbed from 9.0 to 17.9 per 100,000/year between 2002–03 and 2017–18 (annual increase of 5.3%). In Germany, incidence tripled from 3.4 to 10.8 per 100,000 in 10–19-year-olds between 2002 and 2020. Period: 2001 → 2017 (prevalence); 2002 → 2018 (incidence). Demographics most affected: Black youth (37.8 per 100,000), American Indian/Alaska Native (32.8), and Hispanic youth (20.9) bear vastly disproportionate burdens. Females exceed males. For the first time in 2017–18, T2D incidence in US youth aged 15–19 surpassed T1D incidence. Vitamin D connection: Vitamin D deficiency impairs insulin secretion via pancreatic beta-cell VDR expression and worsens insulin resistance. Systematic reviews confirm an inverse association between serum 25(OH)D and both metabolic syndrome and T2D. The demographics hardest hit — darker-skinned youth — are precisely those with the lowest vitamin D synthesis capacity.

3. Celiac disease

Increase: 2.2–2.65×. In the UK, Conrad et al. (Lancet, 2023) — analyzing 22 million electronic health records — found the age-/sex-standardized incidence rate ratio was 2.19 comparing 2017–19 to 2000–02. In US children (Olmsted County, MN), incidence rose from 8.1 to 21.5 per 100,000 between 2000–02 and 2011–14, a 2.65× increase (Alkhiari et al., JPGN, 2017). A global meta-analysis found an average 7.5% annual increase in celiac incidence over recent decades (King et al., Am J Gastroenterol, 2020). Period: 2000 → 2019 (UK); 2000 → 2014 (US pediatric). Demographics most affected: Children (incidence 21.3 vs. 12.9 per 100,000 in adults); females (17.4 vs. 7.8 per 100,000 in males). Vitamin D connection: VDR polymorphisms are associated with celiac risk. Vitamin D deficiency is both a cause and consequence (via malabsorption) in celiac patients, and vitamin D modulates gut mucosal immunity and intestinal barrier integrity.

4. Pediatric inflammatory bowel disease

Increase: 2.33× in prevalence. Ye et al. (Inflammatory Bowel Diseases, 2020) found US pediatric IBD prevalence increased from 33 per 100,000 (2007) to 77 per 100,000 (2016) — a 133% increase across two large claims databases. A systematic review of 37 studies found 84% reported significant increases in pediatric IBD incidence globally (Kuenzig et al., Gastroenterology, 2022). Crohn's disease was twice as prevalent as UC among children (45.9 vs. 21.6 per 100,000). Period: 2007 → 2016 (US prevalence). Demographics most affected: Children and adolescents across all regions, with the most rapid acceleration in newly industrialized countries. Vitamin D connection: Among the strongest of any GI condition. IBD patients are consistently vitamin D–deficient. Vitamin D suppresses Th1/Th17 inflammatory responses and enhances regulatory T cells in the gut mucosa. Meta-analyses show an inverse association between vitamin D levels and disease activity, and supplementation trials demonstrate improvement in inflammatory markers.

5. Adolescent major depressive episodes

Increase: ~2× overall; exactly 2× among girls. NSDUH data covering 167,783 adolescents aged 12–17 showed MDE prevalence doubled from 8.1% (2009) to 15.8% (2019). Among adolescent females specifically, prevalence rose from 11.4% to 23.4% (Daly, Journal of Adolescent Health, 2022). CDC YRBS data show persistent sadness/hopelessness increasing from ~30% (2013) to 42% (2021). Over 5.2 million US teens experienced an MDE as of 2024. Period: 2009 → 2019. Demographics most affected: Adolescent girls (23.4% MDE rate, double that of boys); LGBTQ+ youth (54% reporting depression symptoms in 2023); increases across all racial/ethnic groups. Vitamin D connection: Vitamin D plays established roles in serotonin synthesis and neuroinflammation regulation. Meta-analyses link low prenatal vitamin D to increased risk of mood disorders in offspring. GBD 2019 data show highest depression incidence rates in high-latitude, high-SDI regions — consistent with the vitamin D–latitude gradient.

6. Gestational diabetes mellitus

Increase: ~2×. US national data show GDM prevalence climbed from approximately 4.2% (2003–04) to 8.2% (2016), and CDC NVSR reported 7.8% in 2020 — up 30% from 2016 alone. By 2022, the rate reached 81 per 1,000 live births. In Canada, GDM incidence doubled over 14 years. Taiwan reported a 1.8× increase from 2004 to 2018. Period: 2003 → 2016 (US). Demographics most affected: Asian women (14.9%, highest among all groups), women with BMI ≥25, and women of advanced maternal age. Rising across all racial/ethnic groups. Vitamin D connection: Well-established. Vitamin D deficiency is linked to impaired glucose tolerance during pregnancy. Meta-analyses confirm maternal vitamin D deficiency increases GDM risk, and supplementation trials show improved glycemic parameters.

7. Thyroid cancer (all ages, especially young women)

Increase: ~2× in the US; >7× in South Korea. US SEER data show incidence approximately doubled from ~7–8 per 100,000 (~2000) to ~15–16 per 100,000 (~2013–14). In South Korea, age-standardized incidence surged from 6.3 (1999) to 47.5 per 100,000 (2009). In adolescents/young adults (0–39), thyroid cancer incidence increased 137% from 1995 to 2014. Period: 1999 → 2013 (US); 1999 → 2009 (South Korea). Demographics most affected: Young women predominantly (females ~3× higher incidence than males). Vitamin D connection: An umbrella review of 71 systematic reviews (2024) found "strong evidence" that maintaining sufficient vitamin D levels lowers thyroid cancer risk (OR = 0.76, 95% CI: 0.64–0.88). Patients with thyroid cancer consistently exhibit lower 25(OH)D levels. There is a 4.7× increase in thyroid nodules among those with low vitamin D. Caveat: Largely attributed to overdiagnosis via increased ultrasonography. Mortality has remained stable. The South Korean spike reversed after screening guidelines changed.

8. Kidney cancer in young adults

Increase: 2× in ages 20–39. Palumbo et al. (Cancer Epidemiology, 2020) documented renal cell carcinoma incidence rising from 0.4 per 100,000 (2000) to 0.8 per 100,000 (2016) in US adults aged 20–39 — an AAPC of +5.0% (p<0.001). In England, early-onset kidney cancer increased 155% in those under 50 (1985–2020). Period: 2000 → 2016 (US SEER). Demographics most affected: Males (58.5%); American Indian/Alaska Native populations show the highest incidence; non-Hispanic Black men show the highest age-standardized rate. Vitamin D connection: The same 2024 umbrella review found "highly suggestive evidence" for vitamin D's role in renal cell cancer prevention, with the same combined OR of 0.76 (95% CI: 0.64–0.88) as thyroid cancer. A 2025 MDPI systematic review confirmed a strong inverse relationship between serum 25(OH)D and renal cancer incidence. Caveat: Partly attributable to incidental detection from widespread CT/MRI use. Most detected tumors are early-stage (T1a). Mortality has not increased proportionally.

Qualifying with caveats: clear >2× but weaker vitamin D evidence or reporting confounds

9. Eosinophilic esophagitis

Increase: ~21× in the Netherlands (2000→2019), from ~0.15 to 3.16 per 100,000 (Navarro et al., Neurogastroenterol Motil, 2021). US EoE-associated ED visits tripled from 2,934 (2009) to 8,765 (2019). This is one of the most rapidly rising diagnoses in gastroenterology. Period: 2000 → 2019. Demographics: Males (2.5:1 ratio), adults 18–64, White populations. Vitamin D connection: Emerging. Dellon et al. (2024) found mean 25(OH)D was 10.8 ng/mL lower in EoE patients vs. controls. EoE is Th2-mediated, and vitamin D regulates eosinophil function and Th2 pathways. A case report documented complete EoE resolution with vitamin D supplementation alone. Evidence remains limited and partly confounded by restrictive elimination diets.

10. Sjögren's syndrome

Increase: 2.09×. Conrad et al. (Lancet, 2023) — the gold-standard 22-million-patient UK study — found an incidence rate ratio of 2.09 comparing 2017–19 to 2000–02. Period: 2000 → 2019 (UK). Demographics: Women (9:1 female-to-male ratio). Vitamin D connection: Documented deficiency in Sjögren's patients; possible link to associated neuropathy and lymphoma risk. Less extensively studied than MS/T1D/IBD.

11. Graves' disease

Increase: 2.07×. The same Conrad et al. Lancet study found an IRR of 2.07 (2000–02 vs. 2017–19). Period: 2000 → 2019 (UK). Demographics: Women predominantly. Vitamin D connection: Vitamin D deficiency is common in autoimmune thyroid disease. VDR polymorphisms have been studied in relation to Graves' disease risk. The association is documented but less robust than for other autoimmune conditions.

12. Pediatric-onset multiple sclerosis

Increase: ~4.3×. The Atlas of MS (3rd edition, Walton et al., 2020) documented global pediatric MS cases rising from ~7,000 (reported by 34 countries in 2013) to ≥30,000 (reported by 47 countries in 2020). US MS prevalence nearly doubled to 913,925 in 2019. The female-to-male ratio has widened from 1.4 (1955) to over 4:1 in some countries. Period: 2013 → 2020 (global pediatric). Demographics: Young women (20–35), higher latitudes, increasingly children. Vitamin D connection: Among the strongest of any autoimmune disease. MS follows a clear latitude gradient. Multiple meta-analyses confirm low 25(OH)D as a risk factor. The VITAL trial showed vitamin D supplementation reduces overall autoimmune disease incidence by 22%. Mendelian randomization studies support a causal role. VDR polymorphisms are associated with MS susceptibility. Caveat: The 4.3× increase partly reflects improved recognition, expanded diagnostic criteria (including MRI), and more countries reporting. Adult MS prevalence increased a more modest ~30% from 2013 to 2022.

13. Pancreatic cancer in young women

Increase: 2.1× in women aged 15–39. Patel et al. (Annals of Internal Medicine, 2024) documented incidence rising from 3.3 to 6.9 per million (2001–2019), with an AAPC of 4.8%. Early-stage small tumors (≤2 cm) increased 8-fold in women. Period: 2001 → 2019. Demographics: Young women most affected; disproportionate increase in Black women. Vitamin D connection: A meta-analysis of 25 studies found reduced pancreatic cancer risk with higher vitamin D. The highest vs. lowest quintile of 25(OH)D showed a 3-fold decreased risk (Stolzenberg-Solomon et al., Am J Epidemiol, 2010). However, NCI notes some studies suggest possible harmful associations at very high levels — evidence is mixed. Caveat: The increase is "primarily due to increased detection of smaller, early-stage endocrine tumors and solid pseudopapillary neoplasms, NOT adenocarcinoma." Mortality remained stable, suggesting overdiagnosis.

14. ADHD in girls and women (UK data)

Increase: 4× in girls under 18; 2× in boys under 18; ~15–20× in adults. McKechnie et al. (BJPsych Open, 2023), analyzing 7.66 million UK primary care records, found new ADHD diagnoses in females under 18 quadrupled from 2000 to 2018. ADHD medication prescribing in girls increased nearly 9-fold. In the US, overall childhood ADHD prevalence increased from ~6–8% (2000) to 11.4% (2022) — approaching but not definitively reaching 2× nationally. Period: 2000 → 2018 (UK). Demographics: Girls and women seeing fastest acceleration; boys still have higher absolute prevalence. Vitamin D connection: A major Danish study (71,793 subjects, 2025) found neonatal vitamin D deficiency increased ADHD risk. Meta-analyses suggest prenatal vitamin D is associated with better cognitive development and lower ADHD risk. Vitamin D is involved in dopamine synthesis and brain development.

15. Food-induced anaphylaxis in children

Increase: >3× in the UK; >2× in the US. UK food anaphylaxis hospital admissions rose from 1.23 to 4.04 per 100,000/year (1998–2018); in children under 15, the increase was from 2.1 to 9.2 per 100,000 — over 4× (Imperial College London, BMJ, 2021). In the US, emergency treatment for food-induced anaphylaxis increased 377% between 2007 and 2016. Peanut allergy incidence in 1-year-olds tripled from 2001 to 2017. Period: 2000 → 2018 (UK); 2007 → 2016 (US). Demographics: All children; Black American children show fastest increases; 8% of US children now have food allergies. Vitamin D connection: Supported by a strong latitude gradient in EpiPen prescriptions and anaphylaxis rates (Camargo et al., Mullins et al.). NHANES 2005–06 data linked low vitamin D to food and environmental allergies in children. A Korean study found lower solar radiation regions had both lower vitamin D and higher food anaphylaxis rates. However, a 2017 systematic review/meta-analysis did not find a statistically significant direct association between vitamin D status and food allergy.

16. Rickets resurgence

Increase: 380% in UK East Kent (2019→2023); UK national rates are now the highest in five decades. US data from Olmsted County, MN document a dramatic increase in nutritional rickets since 2000. Period: 2019 → 2023 (regional UK); post-2000 (US). Demographics: Dark-skinned children, exclusively breastfed infants without supplementation, ethnic minority groups in Northern Europe and Australasia. Vitamin D connection: Direct causal relationship. Rickets is the clinical manifestation of severe vitamin D deficiency. This is definitional. UK surveillance (2015–17) found 77.6% of affected children were not taking vitamin D supplements. The majority were Black (43%) or South Asian (38%). Caveat: Comprehensive national incidence registries are lacking. Most data comes from regional hospital systems and case series, making precise population-level quantification difficult.

Several notable near-misses fell short of the 2× post-1999 threshold

Early-onset colorectal cancer — the poster child of the "early-onset cancer epidemic" — doubled from its 1987 nadir of 4.5 per 100,000 to 9.4 per 100,000 in 2022. From a 2000 baseline, the increase is approximately 40–60%, falling well short of 2×. The vitamin D evidence is among the strongest of any cancer (pooled analysis of 17 cohorts, McCullough et al., JNCI, 2019), making this a condition to watch as the post-2000 trend continues to accelerate. Type 1 diabetes increased ~47% in US youth prevalence (1.5 per 1,000 in 2001 → 2.2 per 1,000 in 2017) — substantial but not 2×. Systemic lupus reached ~1.9× in some datasets. Childhood obesity rose from 13.9% (1999–2000) to 19.7% (2017–2020) — a 42% increase despite its massive public health significance and well-documented vitamin D links. NAFLD prevalence grew ~50–60% from early-2000s baselines. All of these are climbing and may cross the 2× threshold in coming years.

Additionally, the Nature Reviews Clinical Oncology landmark paper (Ugai et al., 2022) identified 14 early-onset cancers that have approximately doubled in adults under 50, including colorectal, breast, endometrial, esophageal, bile duct, gallbladder, head/neck, kidney, liver, myeloma, pancreatic, prostate, stomach, and thyroid cancers. However, these trends are described as rising "since the 1990s," with baselines likely in the early-to-mid 1990s, so they cannot be cleanly attributed to a post-1999 start year. VitaminDWiki catalogs all 14 on its dedicated page connecting them to the vitamin D hypothesis.

What ties these conditions together

The 16 qualifying conditions span virtually every organ system — the gut (celiac, IBD, EoE), the endocrine system (T2D, GDM, Graves', thyroid cancer), the immune system (MS, Sjögren's, food anaphylaxis, rickets), the brain (ASD, ADHD, depression), and solid tumors (kidney, pancreatic).

What they share is a convergence of three features:

rising incidence concentrated in younger populations and women,
disproportionate impact on darker-skinned and higher-latitude groups, and
biological pathways in which vitamin D plays a documented regulatory role
— whether through VDR-mediated gene transcription, immune modulation, insulin signaling, or serotonin synthesis.

This does not prove vitamin D deficiency is driving these epidemics.

Diagnostic changes,
screening intensity,
obesity,
ultraprocessed diets,
the microbiome, and
reduced outdoor time all plausibly contribute.

But the specificity of the demographic overlap is notable: the populations experiencing the steepest vitamin D declines (dark-skinned individuals, indoor-bound youth, higher-latitude residents, the obese) are often the same populations showing the sharpest disease increases. The VITAL trial's demonstration that vitamin D supplementation reduced autoimmune disease incidence by 22% over five years provides the first randomized evidence that at least part of this association may be causal.

The policy implication is straightforward even without definitive proof: population-wide vitamin D optimization is low-cost, low-risk, and addresses a deficiency that is now nearly universal. Whether it meaningfully bends these disease curves remains the central unanswered question — but the associational evidence compiled here suggests the hypothesis deserves far more rigorous testing than it has received.

A reader asked why women and children were so prominent, so I asked Claude, the author

You produced the content of Incidence of 17 Vitamin D-associated health conditions has at least doubled since 1999 . I was asked why it seemed to emphasize women and children over men and seniors. Perhaps there is more concern about the health of women and children, thus more research. What are your thoughts?

Claude: This is a genuinely interesting methodological and sociological question. There are several converging reasons why vitamin D research skews toward women and children, and I think your instinct is partly right, but the full picture is more layered.

Why women are overrepresented in vitamin D research:

Pregnancy and maternal outcomes generate enormous research interest because a single intervention (supplementing the mother) can protect two people simultaneously — arguably the highest leverage point in all of preventive medicine. Preeclampsia, gestational diabetes, preterm birth, and infant bone development all get studied together.
Osteoporosis is disproportionately a women's disease post-menopause, and bone health has historically been the primary clinical justification for vitamin D supplementation. This pulled decades of research attention.
- Autoimmune disease burden — MS, lupus, rheumatoid arthritis, thyroid disease — falls heavily on women, and vitamin D's immunomodulatory role makes it a natural candidate to study in these populations.
- Healthcare utilization: Women engage with the healthcare system more frequently (OB/GYN, well-woman visits, pediatric caregiving roles), creating more research recruitment opportunities.

Why children are overrepresented:

( Rickets was the original motivating disease for vitamin D research, so pediatric bone development has a century-long research legacy. * Developmental windows — autism, ADHD, asthma, allergies — are only measurable in children, and these conditions have all risen dramatically since 1999. * Ethical and policy appeal: Intervening in children is seen as high-value because you're potentially preventing a lifetime of disease burden. Funders and IRBs respond to this framing. * Schools and pediatric clinics are convenient research recruitment venues.

Why men and seniors are underrepresented — the more interesting problem:

Men's health research generally receives less funding per capita than women's health, particularly for non-cancer conditions.
Seniors face a paradox: They are the highest-risk group for vitamin D deficiency (reduced skin synthesis, less outdoor activity, reduced renal activation) and bear the greatest disease burden from the conditions in your list — yet they are harder to recruit into trials (comorbidities create confounders, polypharmacy complicates results, ethical concerns about placebo arms).
Survivorship bias: The seniors most severely deficient may already be institutionalized or deceased, leaving a healthier-than-representative study population.
Cardio and cognitive outcomes most relevant to older men (heart disease, dementia, prostate cancer) do have substantial vitamin D literature, but it tends to be fragmented across specialty silos rather than assembled as a coherent vitamin D story.