Vitamin D – the “sunshine” vitamin – is literally my favorite vitamin in the whole wide world (although technically it’s actually a hormone, not a vitamin). And now, the world is finally giving vitamin D the place in the sun it deserves.
The UK is giving all vulnerable citizens a bottle of Vitamin D this winter (1). An international group of health, science and medical experts (including me!) have signed an open letter to world governments that Vitamin D should be prioritized for ALL healthy adults (2,3) – and let’s please not forget children!
As a holistic pediatrician and pediatric functional medicine expert, I believe that:
Vitamin D is the single MOST important vitamin that you can give your children (and yourselves) this winter.
Vitamin D & SARS-CoV-2
The case for Vitamin D and COVID-19 is increasingly compelling. There are many ongoing studies around the world to clarify appropriate Vitamin D prevention and treatment guidelines. In the meantime, several studies have already demonstrated a correlation between Vitamin D and COVID-19 (4):
- Vitamin D deficiency may increase the risk of contracting COVID-19 (5, 6, 7)
- Low Vitamin D levels may worsen COVID-19 disease severity (8) and increase risk for ICU admission and intubation (9).
- Vitamin D supplementation may reduce the risk of ICU admission (10).
- Vitamin D supplementation, taken either regularly over the preceding year or after diagnosis with COVID-19, improved survival among hospitalized elderly COVID-19 patients (11).
- Asymptomatic or mildly symptomatic COVID-19 patients given short-term, high-dose Vitamin D supplementation were more likely to be SARS-CoV-2 PCR-negative by day 21 with lower levels of an inflammatory marker, fibrinogen (12). The dosage used was Vitamin D3 60,000IU daily for 7 days to reach a 25(OH)D level of >50 ng/ml.
- Low Vitamin D levels are associated with increased COVID-19 mortality in several European countries (13, 14, 15).
Vitamin D – Not Just for COVID-19
Vitamin D isn’t beneficial just for COVID-19. Let’s take a look at some of the other very important reasons that our kids need Vitamin D NOW:
- Vitamin D can protect against influenza and other winter respiratory illnesses and reduce wheezing in children (16, 17, 18)
- Vitamin D optimizes brain development (19)
- Vitamin D helps relieve anxiety/depression and OCD (20, 21, 22)
- Vitamin D improves attention/focus (23, 24, 25)
- Vitamin D supports healthy sleep (26, 27, 28, 29)
- Vitamin D supports immune function in pediatric autoimmune disease, including PANS/PANDAS, juvenile arthritis, type 1 diabetes, lupus, multiple sclerosis, dermatomyositis and alopecia areata (30, 31, 32, 33, 34, 35, 36)
These are ALL concerns that have been exponentially compounded by the pandemic, especially for our children.
1 in 4 teenagers has an anxiety disorder – a number which has been climbing since the start of the pandemic. Suicide is the 2nd leading cause of death among our youth, and the number of teenagers who have contemplated self-harm in the last month has increased at an alarming rate.
African American and Hispanic children are especially at risk for Vitamin D deficiency – could this be one of the reasons they make up 75% of all COVID-related pediatric deaths, despite making up only 40% of the US population of children?
Chronic childhood disease and autoimmunity are at an epidemic high. Currently over 1 in 2 children are diagnosed with a chronic condition. By 2025, that number is projected to be 8 in 10 (37). Eczema is now considered an autoimmune condition (38), affecting up to 1 in 5 infants and children worldwide. (39)
Could Vitamin D be one of the answers to ending our epidemic of chronic childhood disease?
Risk Factors for Vitamin D Deficiency in Your Child
Vitamin D deficiency is one of the most common nutrient deficiencies in children.
Who is at risk for Vitamin D deficiency?
But in particular, the following factors are tip-offs that your child may be at risk for Vitamin D deficiency:
- Maternal Vitamin D deficiency during pregnancy. Vitamin D deficiency in pregnant mothers may be linked with a higher risk for their children developing asthma (40), autism (41), ADHD (42), behavioral problems (43), and diabetes (44). DR. SONG’S TIP: Optimizing Vitamin D during pregnancy is one of the most important ways to support your baby’s developing brain and immune system.
- Being exclusively breastfed – The American Academy of Pediatrics recommends that all breastfed babies receive 400IU of Vitamin D3 daily. I believe that this risk factor comes out of the fact that many pregnant and nursing women are deficient or insufficient in Vitamin D. If nursing mothers had optimal Vitamin D levels, I believe that their breast milk should have adequate Vitamin D to nourish their babies without supplementation. DR. SONG’S TIP: Breastfeeding takes a lot out of mamas, literally! Make sure to optimize your Vitamin D levels if you’re nursing, for your AND your baby’s benefit, in addition to supplementing your baby with 400IU of Vitamin D3 daily.
- Darker pigmented skin
- Limited sun exposure on the skin (due to sunscreen, clothing, etc.)
- Frequent illnesses
- Eczema, asthma or allergies
- Attention and focus concerns
- Anxiety, depression or mood issues
- Autoimmune illness
- Irritable bowel symptoms
- Easy or frequent fractures
- Certain medications (including topical, inhaled, and intranasal steroids; seizure medications; antifungal medications; and antiretroviral medications)
Diagnosing Vitamin D Deficiency
Vitamin D status can be assessed through blood 25-hydroxy-Vitamin D levels, 25(OH)D. Unfortunately, there’s no other way to accurately know your Vitamin D status. As a holistic pediatrician, I consider testing 25(OH)D both routine and essential for optimal health. Many parents are surprised at how low their children’s Vitamin D levels are, even in the middle of the summer when their children have been running around outdoors in the sunshine all day long. It can be even more surprising how much Vitamin D supplementation is needed to actually achieve optimal levels.
Optimal Vitamin D Levels
Most labs report “normal” levels of 25(OH)D as a reference range of::
20 ng/ml – 100 ng/ml (or 50 nmol/l – 250 nmol/l)
That’s a pretty wide range. NOTE: Pay attention to the unit of measurement reported. The United States measures Vitamin D in nanograms per milliliter (ng/ml) while most other countries use nanomoles per liter (nmol/l). To convert from ng/ml to nmol/l, use this formula:
1 ng/ml = 2.5 nmol/l
Most experts would agree that below 10 ng/ml (25 nmol/l) is deficient. But what level is considered sufficient or even optimal varies widely, and likely depends on many factors, including age, gender, race/ethnicity, weight, and underlying health status.
The National Academy of Sciences, Engineering, and Medicine (NASEM) defines Vitamin D deficiency and inadequacy as follows (45):
- Vitamin D deficiency: 25(OH)D levels < 12 ng/ml (<30 nmol/l)
- Vitamin D inadequacy: 25(OH)D levels 12-20 ng/ml (30-50 nmol/l)
However, these guidelines are based on 1976 findings (46) for Vitamin D levels associated with rickets (a severe Vitamin D deficiency bone disease) – WITHOUT taking into account the varied non-skeletal benefits of Vitamin D as one of the most important nutrients for nearly all of our organ systems.
The National Health and Nutrition Examination Survey (NHANES) defines Vitamin D deficiency and insufficiency as follows:
- Vitamin D deficiency: 25(OH)D levels <15 ng/ml
- Vitamin D insufficiency: 25(OH)D levels 15-29 ng/ml
An NHANES study between 2001-2004 (47) found that 9% of all children aged 1-21 years had Vitamin D deficiency and 61% had Vitamin D insufficiency. That’s nearly 3 out of 4 US children (58.4 million children) with Vitamin D deficiency/insufficiency, with many more children likely with suboptimal levels.
Functional and holistic medicine is concerned with not just what’s “normal” or “sufficient” – but what is OPTIMAL.
So what Vitamin D level is OPTIMAL? This is where the controversy abounds … One of the major problems is that studies, for the most part, focus on how to avoid deficiency states. After all, the Recommended Dietary Allowances (RDAs) of nutrients were developed during World War II as guidelines for the minimal requirements to prevent nutrient deficiency diseases like scurvy – NOT the requirements required for OPTIMAL HEALTH.
I don’t know about you, but I don’t want me or my kids living at just above the level of a deficiency disease!
Evidence-based medicine (48) has been defined as “the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. … [It] means integrating individual clinical expertise with the best available external clinical evidence from systematic research.
While there is no clear consensus on ideal 25(OH)D levels, the best clinical evidence from systematic research suggests that optimal 25(OH)D levels are GREATER than 30 mg/ml (49). And as a holistic pediatrician and pediatric functional medicine expert with over 20 years of clinical experience, my individual clinical expertise demonstrates that my patients do best with 25(OH)D levels of 60-80 ng/ml.
Using an evidence-based, integrative & functional medicine approach, I have found OPTIMAL Vitamin D levels to be 60-80 ng/ml for most of my patients.
The Sunshine Vitamin – Can the sun really give us enough Vitamin D?
Ultraviolet-B (UVB) radiation from the sun at wavelengths of 290-315nm is the main non-dietary source of Vitamin D. With UVB exposure, the skin converts 7-dehydrocholesterol to pre-vitamin D3, which then gets converted to 25-hydroxyvitamin D in the liver and subsequently to 1,25-dihydroxyvitamin D in the kidneys.
There are many reasons why most people will not get sufficient Vitamin D levels from sunshine alone (50) :
- The further away from the equator we live, the weaker the sun’s ability to convert Vitamin D through our skin in any season except the summer (that’s most of the Northern Hemisphere, like here in the United States).
- The darker our skin, the less potential we have to synthesize Vitamin D due to increased levels of melanin – a protective pigment that blocks UV radiation from the sun.
- Pollution blocks UVB from reaching our skin, so don’t count on those Spare the Air Days for skin conversion.
- The current recommendation of 10-20 minutes daily of sun exposure during the summer months does NOT adequately boost overall 25(OH)D levels. In fact, the amount of sun exposure required to achieve sufficient levels would likely “compromise skin health.” (51)
Vitamin D Food Sources
Food is medicine, and ideally we would obtain all of our nutrients from food. However, the sad truth is that even with the most varied diet, most of us do not meet our optimal nutritional needs with food alone. Our soil has become depleted so our food is not as nutrient-dense as it once was, and our modern world demands higher nutrient needs for us to stay well. Apart from cod liver oil, fatty fish and mushrooms (not the most kid-friendly foods!), most Vitamin D-rich foods contain relatively low levels of Vitamin D in typically consumed quantities.
That being said, prioritize Vitamin D-rich foods in your child’s diet, with the caveat that many children with chronic physical and mental health concerns have dairy sensitivities, which leaves cow’s milk products out for many children as an option for a Vitamin D-rich food source. Foods highest in Vitamin D include (52):
- Cod liver oil (1 tablespoon (15ml) – provides up to 1,360IU of Vitamin D)
- Salmon and other fatty fish like trout and mackerel (3 ounces – provides up to 650IU of Vitamin D)
- Sardines (1.7 ounces – provides up to 250IU of Vitamin D)
- Shrimp (5 large – provides up to 200IU of Vitamin D)
- White Mushrooms (½ cup raw, sliced – provides up to 366IU of Vitamin D)
- Eggs (1 large – provides up to 44IU of Vitamin D)
- Caviar (1 tablespoon – provides up to 37IU of Vitamin D)
- Liver (3 ounces – provides up to 42IU of Vitamin D)
- Cow’s milk (8 ounces -provides up to 120 IU of Vitamin D)
- Cheese (1 ounce – provides up to 12 IU of Vitamin D)
Vitamin D Supplements are Usually Needed – but how much?
As always, check with your physician before starting any dietary supplements for you or your child. While Vitamin D toxicity is extremely rare at the dosages outlined below, increased risk for toxicity may exist with obesity, chronic kidney disease and certain genetic disorders. On the other hand, certain conditions like chronic disease, malabsorption states and Vitamin D Receptor genetic variants may contribute to the need for higher than expected Vitamin D dosing to reach optimal levels.
When supplementing Vitamin D, use Vitamin D3 (cholecalciferol) rather than Vitamin D2 (ergocalciferol). Vitamin D3 is the preferred form of supplementation, is the form made by your skin when exposed to sunlight, and has been shown clinically to be more effective than Vitamin D2 at raising 25(OH)D levels (53).
Ideally, you would check 25(OH)D levels prior to supplementation, and monitor levels regularly until optimal levels are achieved. Knowing that this is not possible for many, the Vitamin D dosages below are ones that should at least maintain current 25(OH)D levels without approaching levels known to cause toxicity. Vitamin D toxicity with 25(OH)D levels of >150 mg/ml is extremely rare (54). Symptoms of Vitamin D toxicity include heart attack, stroke, kidney stones, headache, nausea, vomiting, diarrhea, anorexia, weight loss, and low bone density.
The Institute of Medicine (55) notes the Tolerable Upper Intake Level (UL) of Vitamin D to be 4000IU for teenagers and adults, with lower levels noted for infants and children. For the average adult, a daily intake of 4000IU of Vitamin D corresponds to a mean 25(OH)D level of about 50 ng/ml (125 nmol/L) (56) – not anywhere near the toxic level.
Vitamin D toxicity is rare even at higher dosages. Administration of Vitamin D3 10,000IU daily for 5 months (57) and even 20,000IU daily for at least one year in healthy adult males did not reach toxic levels 25(OH) levels >100 ng/ml. (58)
The Endocrine Society seems to have the most useful evidence-based recommendation for potential skeletal and non-skeletal benefits of Vitamin D in their Clinical Practice Guidelines for the Evaluation, Treatment, and Prevention of Vitamin D Deficiency (59). The Endocrine Society suggests revised Tolerable Upper Intake Levels (ULs) by age as follows:
- Infants up to 6 months: 1000 IU/day
- Infants 6 months to 1 yr: 1500 IU/day
- Children 1-3 years: at least 2500 IU/day
- Children 4-8 years: 3000 IU/day
- Everyone over 8 years: 4000 IU/day
The Endocrine Society further notes that:
“higher levels of 2000 IU/d for children 0–1 yr, 4000 IU/d for children 1–18 yr, and 10,000 IU/d for children and adults 19 yr and older may be needed to correct vitamin D deficiency.”
OK – let me tell you from clinical experience what I find to be the most useful guidelines. In general, a daily dosage of Vitamin D3 to MAINTAIN current 25(OH)D levels is generally 1000IU per 25 pounds of body weight, up to 5000IU daily. Higher initial doses may be needed to get to optimal levels in the first place, but this should only take place with blood 25(OH)D monitoring by your physician.
When you do not have access to 25(OH)D testing for you or your child, the following are likely safe dosages by age:
- 0-1 year: 400-600 IU daily
- 1-6 years: 1,000 IU daily
- 7-12 years: 2,000-3,000 IU daily
- 13-18 years: 3,000-4,000 IU daily
- 19+ years: 4-5,000 IU daily
Do You Need Vitamin K with Vitamin D?
While Vitamin D enhances absorption of calcium into your bloodstream, Vitamin K is needed to efficiently move that calcium into your bones and teeth to maintain healthy blood calcium levels without causing calcium buildup in your blood vessels, which can lead to potentially harmful atherosclerosis and increased risk for coronary artery disease. While this is typically not a concern for children, it is important to supplement with Vitamin K while supplementing with Vitamin D to synergistically optimize both bone and heart health (60).
Vitamin K1 (phylloquinone) is the main dietary source of Vitamin K, found in green leafy vegetables and cruciferous vegetables like kale, spinach, cauliflower, broccoli, cabbage, brussel sprouts and collard greens. Vitamin K2 is found in modest amounts in fermented foods like natto and sauerkraut, and in some animal sources like meat, eggs, and cheese. Interestingly, almost all Vitamin K2 is produced by lactic acid bacteria in our gut, if we have a healthy gut microbiome. (61)
Recommended Adequate Intake for Vitamin K per the Institute of Medicine is as follows:
|Birth to 6 months||2.0 mcg||2.0 mcg|||||
|7–12 months||2.5 mcg||2.5 mcg|||||
|1–3 years||30 mcg||30 mcg|||||
|4–8 years||55 mcg||55 mcg|||||
|9–13 years||60 mcg||60 mcg|||||
|14–18 years||75 mcg||75 mcg||75 mcg||75 mcg|
|19+ years||120 mcg||90 mcg||90 mcg||90 mcg|
While Vitamin K deficiency is uncommon in the United States, I would recommend that all children over 1 take extra Vitamin K with their Vitamin D supplements. Vitamin K2 (menaquinone) is the preferred form for supplementation. Fortunately, many Vitamin D3 supplements are already synergistically combined with the appropriate amount of Vitamin K2.
Choosing a Vitamin D3/K2 Supplement
Your Vitamin D supplement should contain only Vitamin D and a carrier oil (typically olive oil, medium chain triglyceride oil from coconut, or sunflower oil) – and nothing else. No artificial colors, flavors or preservatives. Stay away from polysorbate 80 and any other names you have trouble pronouncing. Your child doesn’t need any added ingredients – some of which can cause allergies and have been found to negatively affect children’s behavior, developing brains and immune systems.
While there are many reputable sources of Vitamin D3/K2, I’ve handpicked the highest quality supplements to take the guesswork out of it for you. My Healthy Kids Happy Kids Vitamin D3/K2 Liquid, and Vitamin D3/K2 Capsules are exactly what I give to my whole family and recommend for all of my patients. You can find more information here: Healthy Kids Happy Kids Online Store.
Help Me Spread the Word
ONE simple intervention – optimizing Vitamin D levels – could have a profound and lasting impact on our children’s overall health & well-being.
Vitamin D for All could be one of the most important public health priorities of our time.
It’s affordable (for most).
So let’s make it affordable for ALL!
If your physician or practitioner has not yet signed the #VitaminDforAll Letter, ask them to review and sign now. Let’s get this in the hands of our elected officials, public health officers, physicians and healthcare workers everywhere.
And be sure to forward my article to any parent or practitioner you know who could benefit.
We’re all in this together.
xo Holistic mama doc – Elisa Song, MD
Vitamin D References
- Healthy Kids Happy Kids online store: https://store.healthykidshappykids.com/