Vitamin D deficiency- The optimization strategies
With vitamin D deficiency we will suffer from a wide range of health issues even if we don’t have a directly visible bone disease.
Milos Pokimica
Written By: Milos Pokimica
Medically Reviewed by: Dr. Xiùying Wáng, M.D.
Updated June 9, 2023Vitamin D is an essential vitamin with many different functions. It is a prohormone, steroid with a hormone-like activity that regulates about 3% of the human genome (Carlberg, 2019). More than 2,000 genes overall. It is essential for different life functions, for instance, one of them is calcium development. Besides calcium metabolism, immune system regulation will be one of vitamin D’s most essential functions. Science so far doesn’t have research for every gene that vitamin D can activate but it is important to understand that without vitamin D level optimization even if we don’t have blatant vitamin D deficiency, we will suffer from a wide range of health issues even if we don’t have a directly visible bone disease. Vitamin D deficiency is a worst-case scenario.
Also, we need to understand that optimizing vitamin D levels is important for the long-term prevention of osteoporosis. Osteoporosis starts long before and lasts for a long time until the visible effects can be diagnosed. Having high bone density in younger years and preventing vitamin D deficiency throughout our entire life will have an impact on bone density in old age. Visible symptoms of vitamin D deficiency rickets that include bone deformities and bone pain, slow growth, fractures, and seizures are already the last stages of chronic deficiency disease. It cannot be cured with vitamin D supplementation and with additional calcium because the damage is already done. Prevention is the only way. The way osteoporosis can be treated is with additional medications that will promote calcium metabolism in the bones. Problem is that taking medication for osteoporosis has other side effects. Some medication like Reclast (zoledronic acid) is even taken intravenously every two years to help prevent it. Vitamin D is a vitamin and that means it is essential for life there is no way that we can avoid that simple fact even if we disregard the effects it has on bone disease. Not optimizing our vitamin D levels is the same as having any other nutrient deficiency of any other essential nutrient with one difference and that is that it takes a little longer time for its effects to be visible but at the same time once when we lose our bone density it is hard to bring it back.
There is one other difference between vitamin D and every other essential nutrient. That difference is that we create our own vitamin D if we have sun exposure so we do not need to ingest it in the food. There is some vitamin D in the foods that we eat and some food products are fortified with it but the level of fortification is not at the optimal level and vitamin D deficiency is rampant in most of the population. In the US around 40% of the population is in the severe vitamin D deficiency category and more than 85% are in the insufficient level category (Carlberg, 2019). Most likely if you do not have a severe deficiency you will still lack an adequate and optimal level of vitamin D for normal body functioning. What causes vitamin D deficiency is a modern way of life, it is a form of maladaptation to our current environment.
So the question arises, how much do we need for optimal health optimization?
In the medical field usual scientific practice is to recommend nutrition intake at the levels that are needed to prevent the disease. It is not an accepted scientific method to recommend the levels that are the most optimal and that we are adapted to in our evolution. It is only the levels that scientists believe are necessary to prevent a pure form of vitamin D deficiency.
Up until recently, the official RDA for vitamin D was considered to be 200 international units a day and that was an average intake for most people. And before that, there was an accepted belief that 100 IU of vitamin D3 is enough to prevent flagrant signs and symptoms of rickets. Because the number of 100 units was enough to prevent bone disease scientists with no real experimentation recommended 200 units just to be safe. They believed that that was more than adequate to satisfy the body’s vitamin D requirement. Then there was a line of experiments when the Institute of Medicine decided to make a recommendation on specific blood levels of vitamin D that should prevent rickets. They calculated that to get to this level most people would require about 600 IUs a day.
Today the RDA is 600 IU a day and that is an official recommendation. With this new RDA, around 40% of Americans still have vitamin D deficiency. The problem is that even these 600 IU’s are far less than what would be the most optimal level in an evolutionary sense. The level that will promote the most health and longevity effects. One way the medicine can determent the most optimal level is by testing for the hormone in the blood called PTH. Our bodies secrete PTH in situations when the body detects that we don’t have adequate levels of active vitamin D3 for bone metabolism in an effort to raise its levels. When levels in the bloodstream go below 20 nanograms/ml our body will start to produce PTH to protect our bones from softening. And this is just bones.
Vitamin D affects our entire genome and most of the organs and their functioning from the brain to muscle tissue. Measuring just its effects on calcium metabolism is still not the optimal strategy.
“Body requires 5- to 10-fold higher intakes than is currently recommended by health agencies. There is now overwhelming and compelling scientific and epidemiologic data suggesting that the human body requires a blood level of 25(OH)D above 30 ng/mL for maximum health. To increase the blood level to the minimum 30 ng/mL requires the ingestion of at least 1000 IU of vitamin D per day for adults.”
(Holick, 2010)
It is also important for immune system function and prevention of autoimmune diseases from allergies to asthma to multiple sclerosis, prevention of cancers of a different type, periodontal disease prevention, depression, obesity, diabetes type 2, and overall mortality. (Glade, 2013)
“Adequate vitamin D status seems to be protective against musculoskeletal disorders (muscle weakness, falls, fractures), infectious diseases, autoimmune diseases, cardiovascular disease, type 1 and type 2 diabetes mellitus, several types of cancer, neurocognitive dysfunction and mental illness, and other diseases, as well as infertility and adverse pregnancy and birth outcomes. Vitamin D deficiency/insufficiency is associated with all-cause mortality.”
(Pludowski et al., 2013)
At one point in the 20th century, even wire cages were affixed to tenement buildings so that people can put babies in there so that babies could benefit from the sun.
Beyond rickets prevention, if we manage to prevent all of the diseases that are caused by vitamin D deficiency, it is still important vitamin for all-cause mortality, meaning it will promote longevity even if we don’t have any disease risk. We will live longer if we have normal and optimized levels. But what exactly are the optimal levels? One way is to measure the level of vitamin D and compare it to different rates of diseases but that does not directly mean that is the optimal level because it is just observation. Vitamin D deficiency might not be the cause. What is needed is clinical trials where you give people D supplements to prove that vitamin D is effective.
In the last 50 years, there are hundreds of clinical trials involving more than 100,000 people so we have the knowledge now. Vitamin D does help in disease prevention, it does promote longevity and it is cheap. The effects are also potent for example 13% in terms of reduction of total mortality (Chowdhury, 2014). The level of reduction that everyday exercise will cause is 11% so the effects are even more pronounced than everyday exercise. Also, the effect is cumulative. And also this is on top of all the benefits we will have on chronic diseases that can deteriorate the quality of life and are not life-threatening like allergies for example. Keep in mind that taking supplemental vitamin D is no excuse to eat one more donut. Healthy eating will have a cumulative effect on vitamin D optimization. In most studies, the levels of vitamin D are also not completely optimized so the reduction in mortality can be higher if we take an adequate level of supplementation. Also, the positive effects are only correlated with supplementation with active D3 type. It is the type derived from plants and animals and not vitamin D2, the type derived from mushrooms.
So how much? The answer is it depends. Two different individuals can get the same dose but will have different levels in the bloodstream. Then it depends on sun exposure, it depends on dietary intake. The optimal level of supplementation can be only measured with a blood test in individual cases. When scientists give recommendations they will be based on relative numbers for the percentage of the population. For example, they will say take “this” amount of it and 3 out of 5 people will have more “that” that level in the bloodstream. It is not the rule but more in line with recommendations. You will have to do a blood test if you want to know the exact level in your blood.
The problem with vitamins is that you can take too much. In the case of vitamin D and its benefits is not as dangerous vitamin as vitamin A for example. If you overdose on vitamin A you can have serious problems. For example, supplemental vitamin E promotes cancer while dietary vitamin E prevents cancer even at the optimal level. We have to analyze the optimal level and then we have to find the optimal supplementation strategy that will in our individual case put us to that optimal level.
With vitamin D it was believed to be a U shape curve. Most of the benefits in the studies will get at around 70 to 80 nmol/L (Bischoff-Ferrari, 2008). This is the optimal level in the blood. For cancer prevention, the level can be as high as 90-120 nmol/l. More than that will have no additional health benefits. Also, very high levels are correlated with a slight increase in mortality. The risk and increase are not substantial but the apparent sweet spot is around 75 or 80 nanomoles per liter [nmol/L] and more than that you will just be wasting money.
Because vitamin D is a hormone not a vitamin per se there was a debate in the scientific community about its toxic level. The good news is that in order to go to the toxic level we will have to do a serious supplemental overdosing in levels of more than 10,000 IU a day for an extended period. In real-life conditions, although it is still a U-shaped curve it is practically an L curve (Garland et al., 2014).
We can get to an optimal dose without the risk of overdosing and that is good news. We don’t have to do testing and worry about overdose as long as we don’t go above the levels of 10,000 IU a day for an extended period of time. Testing is not recommended and it is not necessary, it is expensive and not accurate. If you do testing there will be a variation in results from 2 to 5 times in different laboratories. You can get a result of 30 ng/ml or 120 ng/ml. In all practical sense, testing is useless. So how much should we take?
An intake of no less than 1000 IU of vitamin D3 (cholecalciferol) per day for all adults may bring at least 50% of the population up to 75 nmol/l (30ng/ml). This means 5 out of 10 people will be at an optimal level depending on their skin color, level of sun exposure, and dietary intake and this is for a population in the US. Because essentially there is no risk of excessive intake of vitamin D the supplementation for 100 percent of the population for everyone to be in the optimal range including individuals with zero sun exposure and zero dietary intake, the dose will be 2200IU. For most of the population anywhere in the world to have a value of 80nmol/L or higher may require a daily oral intake of 2200IU.
Because the government doesn’t want people to overdose themselves even if there is no real risk the tolerable upper intake level is currently set at 2000IU/day.
Actual toxicity is not seen below serum values of 250nmol/L, a value that would be produced only at continuing oral intakes in excess of 10,000IU/day.
The margin of toxicity is extensive. So how much should you take? Because it is one of the cheapest supplements the answer is at least 2200IU a day and more if you are obese and more the older you are. If you are 70 years old you will need 3,500IU to reach the same level.
There might be some risks of toxicity if you overdose that science has not determent yet especially in you have some sort of condition. It also has the potential to lower vitamin A levels. That is the reason you don’t want to overdose. There is no need for it. But again overdosing on vitamin D is very hard to do. For example, in a situation where we are exposed to the sun, our body is able to create thousands of units of it in minutes and is able to store it as well. We cannot naturally overdose ourselves with sun exposure. It will just be stored for later use. That means our body will be able to mobilize its own reserves if our daily intake falters temporarily. It is an oil-soluble vitamin and that is the reason obese people need more, in some cases two times more of it to reach the same blood levels. It is a reason for wide confusion and public recommendations that can range from 600IU to 10,000IU.
References:
- Carlberg C. (2019). Nutrigenomics of Vitamin D. Nutrients, 11(3), 676. https://doi.org/10.3390/nu11030676
- Parva, N. R., Tadepalli, S., Singh, P., Qian, A., Joshi, R., Kandala, H., Nookala, V. K., & Cheriyath, P. (2018). Prevalence of Vitamin D Deficiency and Associated Risk Factors in the US Population (2011-2012). Cureus, 10(6), e2741. https://doi.org/10.7759/cureus.2741
- Holick M. F. (2010). Vitamin D: extraskeletal health. Endocrinology and metabolism clinics of North America, 39(2), . https://doi.org/10.1016/j.ecl.2010.02.016
- Glade M. J. (2013). Vitamin D: health panacea or false prophet?. Nutrition (Burbank, Los Angeles County, Calif.), 29(1), 37–41. https://doi.org/10.1016/j.nut.2012.05.010
- Pludowski, P., Holick, M. F., Pilz, S., Wagner, C. L., Hollis, B. W., Grant, W. B., Shoenfeld, Y., Lerchbaum, E., Llewellyn, D. J., Kienreich, K., & Soni, M. (2013). Vitamin D effects on musculoskeletal health, immunity, autoimmunity, cardiovascular disease, cancer, fertility, pregnancy, dementia and mortality-a review of recent evidence. Autoimmunity reviews, 12(10), 976–989. https://doi.org/10.1016/j.autrev.2013.02.004
- Chowdhury, R. (2014). Vitamin D and risk of cause specific death: systematic review and meta-analysis of observational cohort and randomised intervention studies. Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK200718/
- Bischoff-Ferrari H. A. (2008). Optimal serum 25-hydroxyvitamin D levels for multiple health outcomes. Advances in experimental medicine and biology, 624, 55–71. https://doi.org/10.1007/978-0-387-77574-6_5
- Garland, C. F., Kim, J. J., Mohr, S. B., Gorham, E. D., Grant, W. B., Giovannucci, E. L., Baggerly, L., Hofflich, H., Ramsdell, J. W., Zeng, K., & Heaney, R. P. (2014). Meta-analysis of all-cause mortality according to serum 25-hydroxyvitamin D. American journal of public health, 104(8), e43–e50. https://doi.org/10.2105/AJPH.2014.302034
Related Posts
Do you have any questions about nutrition and health?
I would love to hear from you and answer them in my next post. I appreciate your input and opinion and I look forward to hearing from you soon. I also invite you to follow us on Facebook, Instagram, and Pinterest for more diet, nutrition, and health content. You can leave a comment there and connect with other health enthusiasts, share your tips and experiences, and get support and encouragement from our team and community.
I hope that this post was informative and enjoyable for you and that you are prepared to apply the insights you learned. If you found this post helpful, please share it with your friends and family who might also benefit from it. You never know who might need some guidance and support on their health journey.
– You Might Also Like –

Learn About Nutrition
Milos Pokimica is a doctor of natural medicine, clinical nutritionist, medical health and nutrition writer, and nutritional science advisor. Author of the book series Go Vegan? Review of Science, he also operates the natural health website GoVeganWay.com
Medical Disclaimer
GoVeganWay.com brings you reviews of the latest nutrition and health-related research. The information provided represents the personal opinion of the author and is not intended nor implied to be a substitute for professional medical advice, diagnosis, or treatment. The information provided is for informational purposes only and is not intended to serve as a substitute for the consultation, diagnosis, and/or medical treatment of a qualified physician or healthcare provider.NEVER DISREGARD PROFESSIONAL MEDICAL ADVICE OR DELAY SEEKING MEDICAL TREATMENT BECAUSE OF SOMETHING YOU HAVE READ ON OR ACCESSED THROUGH GoVeganWay.com
NEVER APPLY ANY LIFESTYLE CHANGES OR ANY CHANGES AT ALL AS A CONSEQUENCE OF SOMETHING YOU HAVE READ IN GoVeganWay.com BEFORE CONSULTING LICENCED MEDICAL PRACTITIONER.
In the event of a medical emergency, call a doctor or 911 immediately. GoVeganWay.com does not recommend or endorse any specific groups, organizations, tests, physicians, products, procedures, opinions, or other information that may be mentioned inside.
Editor Picks –
Milos Pokimica is a doctor of natural medicine, clinical nutritionist, medical health and nutrition writer, and nutritional science advisor. Author of the book series Go Vegan? Review of Science, he also operates the natural health website GoVeganWay.com
Latest Articles –
Plant Based News
-
Natural Peanut Butter Ice Cream (Vegan)
on August 15, 2025
-
This Summer Paella Is A One-Pan Vegan Feast
on August 14, 2025
-
Aquafaba 101: A Guide To Cooking With Chickpea Water
on August 14, 2025
-
Vegan Michelin-Starred Restaurant Eleven Madison Park Reintroduces Meat
on August 13, 2025
-
‘Breakthrough’ Danish Study Could Transform Animal-Free Cheese
on August 13, 2025
-
Candied Sweet Potato Ice Cream (Dairy-Free)
on August 13, 2025
-
Plant-Based Diets May Cut Cancer Risk By A Quarter, Study Shows
on August 12, 2025
Top Health News — ScienceDaily
- How cats with dementia could help crack the Alzheimer’s puzzleon August 14, 2025
Cats can naturally develop dementia with brain changes strikingly similar to Alzheimer’s disease in humans, including toxic amyloid-beta buildup and loss of synapses. A new study shows these similarities could make cats valuable natural models for research, potentially leading to treatments that benefit both species. The research also revealed that brain support cells may contribute to synapse loss, and findings could help owners recognize and manage dementia symptoms in aging pets.
- Injectable “skin in a syringe” could heal burns without scarson August 14, 2025
Scientists in Sweden have developed a groundbreaking “skin in a syringe” — a gel packed with live cells that can be applied directly to wounds or even 3D-printed into skin grafts. Designed to help the body build functional dermis rather than scar tissue, the innovation combines fibroblast cells on gelatin beads with a hyaluronic acid gel, held together using click chemistry. In a parallel advance, the team also created elastic hydrogel threads that can form tiny, fluid-carrying channels, […]
- The surprising brain chemistry behind instant friendshipson August 14, 2025
UC Berkeley scientists found oxytocin is key for quickly forming strong friendships, but less critical for mate bonds. In prairie voles, a lack of oxytocin receptors delayed bonding and reduced partner selectivity, changing how the brain releases oxytocin and affecting social behavior.
- The 30-minute workout that could slash cancer cell growth by 30%on August 13, 2025
A vigorous workout can spark anti-cancer proteins, cut cancer cell growth, and help survivors fight recurrence by reducing inflammation and improving body composition.
- Blood pressure cuff errors may be missing 30% of hypertension caseson August 13, 2025
Cambridge scientists have cracked the mystery of why cuff-based blood pressure monitors often give inaccurate readings, missing up to 30% of high blood pressure cases. By building a physical model that replicates real artery behavior, they discovered that low pressure below the cuff delays artery reopening, leading to underestimated systolic readings. Their work suggests that simple tweaks, like raising the arm before testing, could dramatically improve accuracy without the need for expensive […]
- Global study reveals the surprising habit behind tough decisionson August 13, 2025
A sweeping international study has revealed that when faced with complex decisions, people across cultures—from bustling megacities to remote Amazon communities—tend to rely on their own judgment rather than seeking advice. The research, spanning over 3,500 participants in 12 countries, challenges the long-held belief that self-reliance is primarily a Western trait. While cultural values influence how strongly individuals lean on their inner voice, the preference for private reflection […]
- The hidden mental health danger in today’s high-THC cannabison August 12, 2025
THC levels in cannabis have soared in recent years, raising the risk of psychosis—especially in young, frequent users. Studies reveal a strong connection between cannabis-induced psychosis and schizophrenia, making early cessation and treatment essential.
PubMed, #vegan-diet –
- Beyond the plate: A pilot study exploring the microbial landscape of omnivores and vegans through amplicon sequencing and metagenomicson August 13, 2025
CONCLUSIONS: These results were consistent with recently published gut microbiome signatures of vegans and omnivores across three different countries. Therefore, this small dataset allows a first insight into the gut microbiota of another county’s omnivores and vegans whereby detailed and relevant dietary, lifestyle and health related characteristics collected in this study aid in understanding of the connection between respective diets and the microbiome.
- Plant-based diets and risk of type 2 diabetes: systematic review and dose-response meta-analysison August 11, 2025
Type 2 diabetes (T2D) incidence has been steadily increasing over the past few decades. Several studies have evaluated the effect of plant-based, vegetarian or vegan diets on the risk of T2D, although their potential benefits need to be confirmed and characterized. We performed a literature search up to July 10, 2025 using the terms/keywords related to plant-based index (PDI), vegetarian/vegan diets, and T2D. We included observational non-experimental studies evaluating adherence to such […]
- Evaluating nutritional and food cost assessments: cash-register receipts may be an alternative for FFQs – accuracy and feasibility in a dietary studyon August 7, 2025
CONCLUSIONS AND IMPLICATIONS: The dietary cost of the ‘FFQ-and-supermarket-prices’ method is more strongly correlated and agreeable with the ‘cash-register-receipts-items’ method when ‘eating-away-from-home’ items are omitted, indicating that ‘eating-away-from-home’ costs are poorly estimated when using the standard ‘FFQ-and-supermarket-prices’ method. Finally, estimating energy, carbohydrates, protein, fat, calcium and iron using ‘cash-register-receipts-items’ is feasible.
- Impact of healthy and sustainable diets on the mortality burden from cardiometabolic diseases and colorectal cancer in Mexican adults: a modeling studyon August 6, 2025
CONCLUSIONS: These findings support the implementation of policies promoting HSDs in Mexico to reduce the burden of cardiometabolic and CRC mortality. Particularly, the MHSDG is a relevant strategy due to its food-system approach, local applicability and cultural alignment.
- Resolution of Chronic Urticaria in a Vegan Patient With Vitamin B12 Supplementation: A Case Reporton August 4, 2025
CONCLUSION: This case underscores the importance of considering vitamin B12 deficiency in the differential diagnosis of chronic urticaria, especially in patients adhering to restrictive diets. Addressing nutritional deficiencies can be a straightforward and effective approach in resolving chronic urticaria symptoms.
Random Posts –
Featured Posts –

Latest from PubMed, #plant-based diet –
- Comparative Analysis of Fecal Microbiota and Metabolomic Profiles in Male and Female Leizhou Goats Offered a 10% Crude Protein Diet Among Four Energy Levelsby Hu Liu on August 14, 2025
The gut microbiota plays a crucial role in maintaining the host’s metabolism and can influence the host’s productivity. Both dietary composition and gender have distinct effects on the composition of the gut microbiota. Therefore, to investigate the differences in the structure and function of the gut microbiota between female and male goats, we analyzed their fecal microbiota and metabolites when fed a 10% crude protein diet at four different energy levels-7.01, 8.33, 9.66, and 10.98 MJ/kg […]
- Impact of a Semi-Virtual Lifestyle Medicine Program on Health Metrics of Metabolic Dysfunctionby Kirk Voelker on August 14, 2025
Introduction: Lifestyle medicine can reduce the risk of developing cardiometabolic disease. Yet, interventions are predominantly designed for rehabilitation, and many struggle with time and location barriers. Virtual health coaching modalities show promise in addressing these barriers. This paper describes the outcomes of a semi-virtual, prevention-focused lifestyle medicine program that ranged from 10-12 weeks. Method: A retrospective, observational study was conducted to examine the impact […]
- Gut-associated bacteria and their roles in wood digestion of saproxylic insects: The case study of flower chafer larvaeby Worarat Kruasuwan on August 14, 2025
Protaetia acuminata (Fabricius, 1775) (Coleoptera: Scarabaeidae) is widely distributed throughout Southeast Asia and plays a significant role in nutrient cycling by facilitating the decomposition of woody materials, a process that likely relies heavily on the contribution of symbiotic bacteria within their digestive system. However, their gut bacteria have not been thoroughly studied. By using V3-V4 amplicon sequencing, it was revealed that the midgut (MG) of Pr. acuminata larvae and […]
- A review of various chromatographic analysis techniques for lignans in plant-derived foodsby Yu-Tong Yang on August 14, 2025
Lignans are naturally occurring compounds found in a variety of plants, and they have garnered significant attention for their health-promoting properties. These bioactive substances are present in numerous food products, both inherently as components of plant-based ingredients like seeds, grains, vegetables, and fruits, and as deliberate additives to enhance nutritional value. The development of analytical techniques for quantifying lignan content in various foods is essential due to the…
- Stearidonic Acid-Enriched Buglossoides arvensis Oil Alleviates High-Fat Diet-Induced Hepatic Lipid Accumulation and Inflammation via AMPK/SIRT1 Activation in Ratsby Mak-Soon Lee on August 14, 2025
CONCLUSIONS: These findings suggest that SBO more effectively mitigates hepatic lipid accumulation and inflammation in rats fed HF diet, a phenomenon partly related to the increased activation of AMPK and SIRT1. This indicates that SBO may provide greater benefits than BO in improving lipid metabolism and inflammatory responses.
- The aryl hydrocarbon receptor: a promising target for intestinal fibrosis therapyby Yiyang Pan on August 14, 2025
Intestinal fibrosis, a severe complication of inflammatory bowel disease, leads to intestinal stenosis. Effective therapies for this condition are lacking. The aryl hydrocarbon receptor (AhR), a highly conserved nuclear transcription factor activated by diverse ligands, plays dual roles in fibrogenesis, but its relationship to intestinal fibrosis has not been comprehensively reviewed. This review explores the pathogenesis of intestinal fibrosis, and places particular focus on the mechanistic…