Morning Sickness might be eliminated by Vitamin D

Hyperemesis Gravidarum is a severe form of Morning Sickness

Is there a correlation between the severity of symptoms and vitamin D levels in pregnancy with hyperemesis gravidarum? - March 2025
Vitamin D and Hyperemesis Gravidarum: Examining the Potential Protective Relationship - April 2025
Hyperemesis Gravidarum 40% more likely if low vitamin D - Dec 2023
- 4 of the references
Is morning sickness associated with low vitamin D (Perplexity AI April 2024 said yes)
Morning Sickness associated with smoking (smoking reduces Vitamin D levels) Dec 2017
VitaminDWiki - Pregnancy category contains
VitaminDWiki – Healthy pregnancies need lots of vitamin D contains

Is there a correlation between the severity of symptoms and vitamin D levels in pregnancy with hyperemesis gravidarum? - March 2025

DOI: 10.4274/tjod.galenos.2025.73848 PDF is online

Objective
This study aimed to investigate the relationship between serum vitamin D levels and the severity of symptoms in individuals with hyperemesis gravidarum (HG).

Materials and Methods
A cohort of eighty patients exhibiting vomiting three or more times daily, positive ketones on complete urinalysis, and oral feeding difficulties were recruited. Symptom severity was assessed using the 8-question Rhodes index, categorizing patients into non-symptomatic, mild, moderate, and severe groups. Serum vitamin D levels were measured using venous blood samples; a deficiency was defined as less than 10 ng/mL, an insufficiency as 10-20 ng/mL, and a normal level as more than 20 ng/mL.

Results
The distribution of symptom severity revealed 14 (17.5%) with mild, 38 (47.5%) with moderate, and 28 (35%) with severe symptoms. Groups showed no significant differences in demographic or obstetric characteristics except for ketone positivity rates (p<0.05). There was a significant difference in vitamin D levels between the severity groups: mild symptoms (32.12±4.02 ng/mL), moderate symptoms (19.98±6.37 ng/mL), and severe symptoms (8.11±3.06 ng/mL) (p<0.001). Vitamin D and the Rhodes index mean score showed a significant negative relationship (r=-0.844, p=0.001). With 96.4% sensitivity and 89.5% specificity, receiver operating characteristic analysis showed that symptom intensity rose when blood vitamin D levels were less than 11.54 ng/mL.

Conclusion
These results highlight a negative relationship between the severity of HG symptoms and serum vitamin D levels. Screening pregnant women

Vitamin D and Hyperemesis Gravidarum: Examining the Potential Protective Relationship - April 2025

Perplexity AI Deep Research April 2025
The relationship between vitamin D levels and hyperemesis gravidarum (HG) has emerged as an area of scientific interest. As a severe form of pregnancy-related nausea and vomiting affecting approximately 0.3-3.6% of pregnant women worldwide, HG leads to significant maternal morbidity and is the primary cause of hospitalization in the first trimester. This report examines current evidence regarding whether vitamin D might reduce HG incidence or severity.

XXX Current Research Evidence on Vitamin D and Hyperemesis Gravidarum
XXX Observational Studies and Their Findings
Multiple studies have investigated the relationship between vitamin D status and hyperemesis gravidarum, though with somewhat inconsistent results. A 2016 prospective case-control study found that while vitamin D levels were lower in women with HG compared to healthy pregnant controls (5.30 μg/L vs. 6.44 μg/L), this difference did not reach statistical significance (p=0.09). The researchers noted that despite the lack of statistical significance, the trend suggested vitamin D might play a role in controlling inflammation associated with HG 1.

Conversely, a 2023 single-center case-control study found no significant difference in serum vitamin D levels between HG patients and controls (p = 0.760). This study also highlighted the prevalence of vitamin D deficiency in their overall pregnant population, with only 17% of all participants having sufficient vitamin D levels (>20 ng/ml), regardless of HG status 3.

Interestingly, another 2023 study reported contradictory findings, observing that vitamin D levels were significantly higher in the HG group compared to the control group (p = 0.001). This study also found elevated procalcitonin (PCT) levels in HG patients, suggesting a potential inflammatory component to the condition 4.

XXX Correlation Between Vitamin D Levels and Symptom Severity
A 2020 study using the Rhodes index to objectively assess symptom severity found a strong negative correlation between vitamin D levels and HG symptom intensity. Patients with mild symptoms had mean vitamin D levels of 32.12±4.02 ng/mL, those with moderate symptoms had 19.98±6.37 ng/mL, and those with severe symptoms had significantly lower levels at 8.11±3.06 ng/mL (p<0.001). This study demonstrated that when serum vitamin D levels fell below 11.54 ng/mL, symptom intensity increased significantly with 96.4% sensitivity and 89.5% specificity 7.

XXX Genetic Evidence for Causality
The strongest evidence supporting a causal relationship comes from a 2023 Mendelian randomization analysis. This research methodology uses genetic variants as instrumental variables to investigate causal relationships. The study found that an increase in 25-hydroxyvitamin D level was associated with a significantly lower risk of hyperemesis gravidarum (odds ratio: 0.568, 95% CI: 0.403-0.800, p = 0.001). This suggests that vitamin D may be causally associated with HG risk in European populations 5.

XXX Potential Mechanisms
XXXX Immunomodulatory and Anti-inflammatory Effects
Vitamin D is recognized as an important immunomodulator and anti-inflammatory agent that may play a critical role in the reproductive system and potentially in HG pathogenesis. Research indicates that vitamin D receptors are present on various immune cells, and vitamin D helps fetal immune adaptation by inhibiting cytokine secretion from T-helper cells 1.

Vitamin D inhibits the secretion of pro-inflammatory cytokines from the placenta and suppresses inflammatory responses, which could be relevant to HG given that immune dysregulation and inflammation have been suggested as crucial factors in its etiopathogenesis 1 7.

XXXX Relationship with Inflammatory Markers
Some research has examined the relationship between vitamin D, inflammatory markers like high-sensitivity C-reactive protein (hs-CRP), and HG. While one study found no correlation between vitamin D and hs-CRP levels in HG patients 1, others have noted that inflammatory processes might be involved in HG pathogenesis, with vitamin D potentially playing a modulatory role 7.

XXX Clinical Applications and Recommendations
XXXX Current Treatment Approaches
Some treatment protocols for HG already include vitamin D supplementation. The Hyperemesis Education and Research Foundation's patient treatment overview recommends vitamin D with vitamin K daily (minimum 2000 IU of vitamin D) as part of nutritional support for HG patients [|12].

XXX Preventive Potential
The 2020 study that found a correlation between vitamin D levels and symptom severity suggested that screening vitamin D levels before pregnancy and providing routine replacement for patients with deficiency might help prevent severe HG symptoms. The authors proposed this approach could potentially reduce hospitalizations and economic expenditures related to HG management 7.

X XXX Broader Context: Vitamin D in Pregnancy
XXX General Benefits of Vitamin D Supplementation
While not specific to HG, numerous studies demonstrate benefits of adequate vitamin D during pregnancy. A recent umbrella review of systematic reviews and meta-analyses reported that vitamin D supplementation in pregnancy increases birth weight and reduces the risk of maternal pre-eclampsia, miscarriage, vitamin D deficiency, and fetal or neonatal mortality 8.

XXXX Prevalence of Deficiency
Vitamin D deficiency is common in pregnant populations globally. In one HG study, 90.0% of women in the HG group and 73.3% in the control group had vitamin D deficiency 1. Another study found that only 17% of pregnant participants had sufficient vitamin D levels, highlighting the need for supplementation regardless of HG status 3.

XXX Limitations of Current Research
XXXX Methodological Considerations
Most studies on this topic have small sample sizes, limiting statistical power. For example, the 2016 prospective case-control study included only 30 women with HG and 30 controls 1. Studies also vary in their definitions of vitamin D deficiency and methodologies for measuring vitamin D levels.

XXXX Conflicting Results
The contradictory findings across studies—with some showing lower vitamin D in HG patients 1 7, others showing higher levels 4, and some finding no difference 3—highlight the complexity of this relationship and the need for larger, more standardized research.

XXX Conclusion
The current evidence suggests vitamin D may play a role in reducing hyperemesis gravidarum risk or severity, though findings are not entirely consistent. The Mendelian randomization study provides the strongest evidence for a causal relationship, indicating that higher vitamin D levels may reduce HG risk 5. The negative correlation observed between vitamin D levels and symptom severity further supports this relationship 7.

Given the high prevalence of vitamin D deficiency among pregnant women and the relative safety of supplementation, ensuring adequate vitamin D status before and during pregnancy appears prudent. This may potentially reduce HG risk or severity, while also providing other well-documented benefits for maternal and fetal health. However, larger prospective studies are needed to definitively establish the relationship between vitamin D and HG and to determine optimal supplementation protocols specifically for HG prevention.

Citations:

Hyperemesis Gravidarum 40% more likely if low vitamin D - Dec 2023

Vitamin D and hyperemesis gravidarum: A mendelian randomization study
J Gynecol Obstet Hum Reprod. 2023 Dec;52(10):102678. doi: 10.1016/j.jogoh.2023.102678
Fang Hu 1

Background: The causality between vitamin D and hyperemesis gravidarum remains unknown. Our aim was to investigate the causal effect of vitamin D on hyperemesis gravidarum using the two-sample Mendelian randomization method.

Methods: Independent single nucleotide polymorphisms significantly associated with serum 25-hydroxyvitamin D levels served as instrumental variables. The corresponding effect estimates for hyperemesis gravidarum were obtained from the Finngen Biobank. For Mendelian randomization analysis, inverse variance weighting was used as the primary method. We also used weighted median, MR-Egger regression, simple mode, and weighted mode as complementary methods to inverse variance weighting. The MR-Egger intercept test, Cochran's Q test, and "leave-one-out" sensitivity analysis were performed to assess the horizontal pleiotropy, heterogeneity, and stability of the causal association between 25-hydroxyvitamin D levels and hyperemesis gravidarum.

Results: We found that an increase in 25-hydroxyvitamin D level was associated with a lower risk of hyperemesis gravidarum odds ratio (OR): 0.568, 95 % CI: 0.403-0.800, p = 0.001. The result demonstrates the causal relationship between 25-hydroxyvitamin D level and the risk of hyperemesis gravidarum in the European population.

Conclusions: The large Mendelian randomization analysis suggests that vitamin D may be causally associated with risk of hyperemesis gravidarum.

Introduction
Hyperemesis gravidarum (HG) is severe nausea and vomiting in pregnancy. Between 0.3 %- 3 % of all pregnant women suffer from HG 1. Worldwide, prevalence rates are higher in women of Asian and Middle Eastern ethnicities, as high as about 10 % in a study of a Chinese population 2. HG can be complicated by dehydration, electrolyte disturbances, poor nutritional intake, weight loss, and requires hospitalization in most cases 3. In addition to the negative effects on maternal, physical, and psychological well-being, HG can impair fetal growth and have negative consequences for the health of the offspring.

Vitamin D, a fat-soluble vitamin, is the collective name for cholecalciferol and ergocalciferol 4. 25-Hydroxyvitamin D (25OHD) is the main form of vitamin D in the human bloodstream and is often used as an indicator for evaluating the nutritional status of vitamin D. Therefore, in this work, we focus on serum 25OHD levels. Evidence is accumulating that vitamin D deficiency increases the risk of adverse perinatal outcomes 5. There are preliminary studies suggesting that vitamin D levels were lower in women with hyperemesis gravidarum compared to others 6. Vitamin D is an immunomodulator that may play a crucial role in the development of hyperemesis gravidarum. Therefore, vitamin D is thought to play a crucial role in controlling the inflammatory status associated with hyperemesis gravidarum.

Because of the special nature of pregnancy, randomization clinical trials researches (RCTs) are limited. In the absence of RCTs, Mendelian randomization (MR) design is an important strategy for causal inference. MR uses genetic variants as proxies for an exposure to predict its causal association with an outcome. This method skillfully exploits the genetic variation's distributive randomness while successfully avoiding confounding biases 7.

Overall, the relationship between vitamin D levels and the risk of HG is still not clear, and further studies are need. In this study, we focused on exploring the causal relationship between serum 25OHD level and the occurrence of HG, which may have significant clinical potential.

Section snippets
Study design
MR is a method for determining the causal relationship between the phenotype of exposure and the outcome by using genetic variants for exposure as instrument variables (IV) 8. This method could use the publicly available dataset from large-sample genome-wide association studies (GWAS) for both “exposures” and “outcomes” and address the common drawbacks of observational studies. To obtain reliable causal relationships, MR studies must meet the assumptions of relevance assumptions (IVs are….

Instrumental variable selection
Independent SNPs were selected from the GWAS dataset, which were associated with the 25OHD serum level at the genome-wide significance level (p < 5 × 10−8) and the low level of linkage disequilibrium (LD) (r2 < 0.001) were related. Removing the following SNPs because they are palindromic and have intermediate allele frequencies: rs10127775, rs5112. The genes in which they occur were queried in Pubmed, and the genes of SNPs that do not belong to a specific gene were defined as NULL. The….

Discussion
The Mendelian randomization study performed an analysis of the causal relationship between vitamin D and HG based on GWAS summary datasets generated by many different consortia including 441,291 individuals using multiple SNPs as instrumental variables. Our results showed a causal relationship between serum 25OHD level and the occurrence of HG…..

A previous research showed that vitamin D levels were lower in women with hyperemesis gravidarum compared to other women although it did not reach….

Conclusion
In the MR study, we found that decreases in serum 25OHD levels were associated with a higher risk of HG, which is consistent with previous studies describing a critical biological role of vitamin D in the development of HG. However, because of the limited availability of evidence from clinical studies, further clinical studies are needed to investigate the benefits of vitamin D for the prevention and treatment of HG…..

Acknowledgments
Data in the European population on serum 25OHD levels are available through the United Kingdom Biobank and data analysis is available through the GWAS database. We thank these researchers for their selfless sharing. Data in the European population on excessive vomiting in pregnancy are available through the GWAS database, we would like to thank the participants and investigators of the FinnGen study.

4 of the references

M.S. Fejzo et al. High prevalence of severe nausea and vomiting of pregnancy and hyperemesis gravidarum among relatives of affected individuals Eur J Obstetric Gynecol Reproduct Biol (2008)
E. Kan et al. Evaluation of relationship between inflammatory markers and hyperemesis gravidarum in patients admitted to emergency department – Am J Emerg Med (2020)
S. Yılmaz et al. – Do vitamin D and high-sensitivity-C reactive protein levels differ in patients with hyperemesis gravidarum? A preliminary study – Turk J Obstet Gynecol – (2016)
K. Maslin, C. Dean (2021)- Nutritional consequences and management of hyperemesis gravidarum: a narrative review - Nutrition Research Reviews, 35

Yes, morning sickness is associated with low vitamin D levels. Several studies have indicated that vitamin D deficiency may play a role in the etiopathogenesis of nausea and vomiting during pregnancy (NVP), commonly referred to as morning sickness.

Is morning sickness associated with low vitamin D (Perplexity AI April 2024 said yes)

Role of Vitamin D in Nausea and Vomiting of Pregnancy: Research has shown that vitamin D has immunomodulatory and anti-inflammatory properties, which are significant during pregnancy. A study highlighted that pregnant women with morning sickness had a higher risk of vitamin D deficiency compared to those without morning sickness. It was found that there was a significant decrease in serum vitamin D3 levels in patients with NVP compared to control groups1.
Clinical Observations and Recommendations: The study from Thi-Qar, Iraq, included clinical observations that supported the association between lower levels of vitamin D and increased severity of morning sickness. This study was among the first to classify the effects of various vitamins and elements on women experiencing NVP1.
Vitamin D Deficiency and Dietary Intake: Another study emphasized the importance of proper nutritional status before and during pregnancy to prevent NVP. It noted that low consumption of vitamin D-rich foods and supplements before pregnancy was associated with vitamin D deficiency, which could exacerbate morning sickness2.
General Findings on Vitamin D in Pregnancy: General medical advice and research also support the notion that vitamin D plays a crucial role in pregnancy, affecting not just the mother's health but also the child's development. Vitamin D helps in the absorption and metabolism of calcium and phosphorus, which are vital for bone health and development11.

In conclusion, while vitamin D deficiency is not the sole cause of morning sickness, it is associated with an increased risk and severity of NVP. Pregnant women are advised to monitor their vitamin D levels and consider appropriate supplementation, as recommended by healthcare providers, to potentially alleviate the symptoms of morning sickness1 2 11.

Morning Sickness associated with smoking (smoking reduces Vitamin D levels) Dec 2017

Link found between morning sickness, smoking and healthy pregnancies
URL

A link between the ‘old wives’ tale that morning sickness may indicate a healthy pregnancy, and the reason smoking is so detrimental has been found, according to a review published in the Journal of Molecular Endocrinology. The article discusses the importance of the hormone endokinin for healthy pregnancies, its role in causing morning sickness, and how its normal function may be adversely affected by smoking, leading to poor outcomes in pregnancy.

Successful and effective implantation of the placenta is essential for a healthy pregnancy but how this is achieved remains to be firmly established. In particular, the role of peptide hormones and the placenta in causing morning sickness is unclear. In this article, Professor Philip Lowry and Dr Russell Woods from the University of Reading review the critical roles that peptide hormones have in ensuring successful implantation of the placenta, discuss how endokinin can indirectly lead to the development of morning sickness symptoms, and how its normal hormone function can be impaired by smoking.

Endokinin is a peptide hormone found throughout the body that can affect blood supply to organs locally. Placental endokinin, even at low levels, appears to be capable of improving local blood flow, which is a key factor for ensuring successful implantation. Endokinin also acts on the brain to induce nausea and vomiting. This is why drugs that block the actions of endokinin in the brain are often used to treat nausea associated with chemotherapy. Furthermore, recent data indicates that tobacco smoke also influences lung endokinin levels.

Since hormones like endokinin are transported in the blood, they can also affect functions in other parts of the body and this is the basis of the link between morning sickness, pregnancy and smoking. Increases in endokinin levels during pregnancy that ensure good placental blood flow can also overspill and activate the brain areas that cause morning sickness symptoms. Similarly, the nausea experienced by non-smokers on inhaling tobacco smoke may be due to raised levels of endokinin in the lungs also activating those brain areas. Given that smoking during pregnancy is well known to lead to poor placental implantation, this suggests that impaired endokinin activity may be involved.

Prof Lowry suggests, “It is feasible that the regular release of lung endokinin into a mother’s blood from smoking adversely affects the normal local response to placental endokinin, which is needed to ensure a healthy pregnancy.”

Prof Lowry cautions, “There may be a temptation to use endokinin blocking drugs to treat morning sickness during pregnancy but these findings suggest that such drugs could affect the health of the pregnancy and must be avoided.”

Prof Lowry concludes, “I hope that this article will give some psychological relief to pregnant women suffering from morning sickness, but will also persuade smokers who are intending to have a baby to kick the habit well beforehand.”

VitaminDWiki - Pregnancy category contains

942 items in Pregnancy category

- see also

Overview Pregnancy and vitamin D
Number of articles in both categories of Pregnancy and:Dark Skin 30; Depression 21; Diabetes 45; Obesity 18; Hypertension 44; Breathing 37; Omega-3 46; Vitamin D Receptor 25 Click here for details
All items in category Infant/Child 866 items
Pregnancy needs at least 40 ng of vitamin D, achieved by at least 4,000 IU – Hollis Aug 2017
38+ papers with Breastfed etc, in the title
Call to action – more Vitamin D for pregnancies, loading doses are OK – Holick Aug 2019
53+ preeclampsia studies
94+ studies with PRETERM in the title
Fertility problem (PCOS) reduced by vitamin D, etc: many studies 15+
94+ Gestational Diabetes
Caesarean birth much more likely if low Vitamin D - many studies 15+ studies
Post-partum depression and low Vitamin D - many studies 15+ studies
Stillbirth reduced by Vitamin D, Zinc, Omega-3 - several studies 5+ studies
Search VitaminDWiki for "Assisted reproduction" 33 items as of Aug 2022
Fertility and Sperm category listing has 146 items along with related searches
(Stunting OR “low birth weight” OR LBW) 1180 items as of June 2020
Less labor pain if higher level of vitamin D – August 2021
Healthy pregnancies need lots of vitamin D
Ensure a healthy pregnancy and baby - take Vitamin D before conception

VitaminDWiki – Healthy pregnancies need lots of vitamin D contains

Most were taking 2,000 to 7,000 IU daily for >50% of pregnancy
Click on hyperlinks for details

Problem	Vit. D Reduces	Evidence
0. Chance of not conceiving	3.4 times	Observe
1. Miscarriage	2.5 times	Observe
2. Pre-eclampsia	3.6 times	RCT
3. Gestational Diabetes	3 times	RCT
4. Good 2nd trimester sleep quality	3.5 times	Observe
5. Premature birth	2 times	RCT
6. C-section - unplanned	1.6 times	Observe
Stillbirth - OMEGA-3	4 times	RCT - Omega-3
7. Depression AFTER pregnancy	1.4 times	RCT
8. Small for Gestational Age	1.6 times	meta-analysis
9. Infant height, weight, head size within normal limits		RCT
10. Childhood Wheezing	1.3 times	RCT
11. Additional child is Autistic	4 times	Intervention
12.Young adult Multiple Sclerosis	1.9 times	Observe
13. Preeclampsia in young adult	3.5 times	RCT
14. Good motor skills @ age 3	1.4 times	Observe
15. Childhood Mite allergy	5 times	RCT
16. Childhood Respiratory Tract visits	2.5 times	RCT

RCT = Randomized Controlled Trial