Vitamin D
The best-established supplement use is preventing rickets/osteomalacia and correcting deficiency. In generally healthy adults with adequate baseline status, modern large trials (VITAL) found no benefit for cancer, cardiovascular events, or fractures — so think 'fix a real deficiency' rather than 'general wellness.'
Quick decision guide
May help most
People with documented low serum 25(OH)D (<50 nmol/L), limited sun exposure, dark skin, age 70+, exclusively breastfed infants, malabsorption (IBD, celiac, bariatric surgery), or chronic kidney/liver disease under medical guidance.
Common dosing range
600–800 IU (15–20 mcg) per day for general use; up to 2,000 IU/day is well within safety margins.
When to expect effects
8–12 weeks for serum 25(OH)D to plateau; weeks–months for clinical effects in deficiency.
Watch out for
Don't exceed 4,000 IU/day long-term without blood testing — chronic excess causes hypercalcemia.
Evidence snapshot
What is it
Vitamin D is a fat-soluble vitamin that the body uses to absorb calcium and maintain bone health. It is unusual among vitamins because the body can make it when skin is exposed to sunlight.
Is it worth it for you?
Use this as a quick fit check, not a diagnosis.
Worth considering if…
Probably skip if…
Evidence at a glance
| Goal | Effect | Best fit | Time |
|---|---|---|---|
Prevention of rickets and osteomalacia Strong Evidence | Near-complete prevention at RDA-level intake (600 IU/day for adults, 400 IU/day for infants). | Exclusively breastfed infants; children and adults with limited sun, dark skin, malabsorption, or chronic kidney disease | Weeks to months for biochemical correction; months for skeletal healing |
Acute respiratory tract infections (deficient adults) Good Evidence | ≈12% relative reduction in any ARI overall; ≈70% reduction in severely deficient (25(OH)D <25 nmol/L) participants | Adults with low baseline 25(OH)D, especially in winter or in northern latitudes | Months — protection accrues over the dosing period, not days |
All-cause mortality (older adults) Good Evidence | ≈6% relative reduction in all-cause mortality with D3; D2 not effective | Older adults (≥65), especially institutionalized women — the population over-represented in the trials | Years of consistent supplementation |
Falls in community-dwelling older adults Limited Evidence | Conflicting — no net benefit per USPSTF; subgroup signals in 800–1,000 IU daily-dose trials in deficient populations | Possibly older adults with documented deficiency receiving daily (not bolus) dosing | Months |
Fracture prevention (non-deficient adults) Limited Evidence | No reduction in fractures vs placebo in non-deficient adults at 2,000 IU/day for 5+ years | Possibly older adults with documented deficiency or osteoporosis on combined Ca + D regimens | Years |
Cancer / cardiovascular event prevention Mixed Evidence | No reduction in invasive cancer or major CVD events at 2,000 IU/day for 5+ years | None established for primary prevention in non-deficient adults | Not established |
Prevention of rickets and osteomalacia
- Effect
- Near-complete prevention at RDA-level intake (600 IU/day for adults, 400 IU/day for infants).
- Best fit
- Exclusively breastfed infants; children and adults with limited sun, dark skin, malabsorption, or chronic kidney disease
- Time
- Weeks to months for biochemical correction; months for skeletal healing
Acute respiratory tract infections (deficient adults)
- Effect
- ≈12% relative reduction in any ARI overall; ≈70% reduction in severely deficient (25(OH)D <25 nmol/L) participants
- Best fit
- Adults with low baseline 25(OH)D, especially in winter or in northern latitudes
- Time
- Months — protection accrues over the dosing period, not days
All-cause mortality (older adults)
- Effect
- ≈6% relative reduction in all-cause mortality with D3; D2 not effective
- Best fit
- Older adults (≥65), especially institutionalized women — the population over-represented in the trials
- Time
- Years of consistent supplementation
Falls in community-dwelling older adults
- Effect
- Conflicting — no net benefit per USPSTF; subgroup signals in 800–1,000 IU daily-dose trials in deficient populations
- Best fit
- Possibly older adults with documented deficiency receiving daily (not bolus) dosing
- Time
- Months
Fracture prevention (non-deficient adults)
- Effect
- No reduction in fractures vs placebo in non-deficient adults at 2,000 IU/day for 5+ years
- Best fit
- Possibly older adults with documented deficiency or osteoporosis on combined Ca + D regimens
- Time
- Years
Cancer / cardiovascular event prevention
- Effect
- No reduction in invasive cancer or major CVD events at 2,000 IU/day for 5+ years
- Best fit
- None established for primary prevention in non-deficient adults
- Time
- Not established
Evidence for 6 uses
AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.
Prevention of rickets and osteomalacia
Corrects deficiencyVitamin D supplementation prevents and treats rickets in children and osteomalacia in adults — both are diseases of impaired bone mineralization caused directly by inadequate vitamin D. This is the original reason vitamin D was identified and the basis for the RDA. The AAP recommends 400 IU/day for all exclusively breastfed infants from birth because breast milk alone doesn't reliably provide enough.
Bottom line: The original and most rock-solid use for vitamin D. If you fit any deficiency-risk profile, the RDA-level dose is non-negotiable.
Acute respiratory tract infections (deficient adults)
Supplement benefitAn individual-participant-data meta-analysis of 25 trials (10,933 participants) found vitamin D supplementation reduced any-ARI risk by 12% overall (aOR 0.88), with a much larger 70% reduction in people who started with serum 25(OH)D <25 nmol/L (severely deficient). A 2021 aggregate-data update with 37 trials found a smaller but still significant 8% reduction. Critically, only daily or weekly dosing worked; large bolus doses did not.
Bottom line: Meaningful protection if you're actually deficient. Daily 600–2,000 IU is what worked in trials — don't expect a one-off mega-dose to do anything.
Evidence is mixed
Editorialists noted heterogeneity is high and the 'any respiratory infection' definition is broad; results have not changed routine clinical practice for non-deficient adults.
All-cause mortality (older adults)
Supplement benefitA Cochrane review of 56 trials (95,286 participants, mostly older women in institutional or community settings) found vitamin D3 — but not D2 — reduced all-cause mortality by about 6% (RR 0.94, 95% CI 0.91–0.98). Effect sizes are modest, and the absolute numbers needed to treat are large. More recent umbrella reviews echo the modest signal but emphasize that trials in selected disease groups have not shown consistent benefit.
Bottom line: Real but modest signal — choose D3 not D2, and don't view this as a reason for non-deficient younger adults to mega-dose.
Falls in community-dwelling older adults
Supplement benefitEarlier trials suggested 700–1,000 IU/day might reduce falls in older adults, likely via effects on muscle strength. But the 2024 USPSTF draft recommendation — informed by larger, lower-bias trials — recommends *against* vitamin D for primary prevention of falls in community-dwelling adults ≥60. Evidence remains mixed, with some recent meta-analyses still finding benefit in moderate-dose, vitamin-D-deficient subgroups.
Bottom line: Don't supplement just to prevent falls. Correct deficiency if present; rely on strength/balance training for fall risk.
Evidence is mixed
USPSTF 2024 recommends against vitamin D for falls in community-dwelling adults; selected meta-analyses still report benefit at 800 IU/day in deficient subgroups. The signal is fragile.
Fracture prevention (non-deficient adults)
Supplement benefitThe 2022 VITAL fracture ancillary (LeBoff et al., 25,871 adults) found 2,000 IU/day vitamin D3 for a median 5.3 years did NOT reduce total, nonvertebral, or hip fractures vs placebo in midlife and older adults without selection for vitamin D deficiency, low bone mass, or osteoporosis. Older fracture-prevention evidence largely combined vitamin D with calcium in institutional populations and may not generalize to today's healthier community-dwelling adults.
Bottom line: If you're not deficient and don't have osteoporosis, supplementing daily vitamin D won't lower your fracture risk.
Cancer / cardiovascular event prevention
Supplement benefitVITAL (2019) — the largest dedicated trial of vitamin D for primary prevention — randomized 25,871 generally healthy adults to 2,000 IU/day D3 vs placebo for a median 5.3 years and found no reduction in invasive cancer or major cardiovascular events. A secondary signal suggested slightly fewer cancer deaths, but this requires confirmation. Earlier observational links between low vitamin D and these outcomes were largely confounded by overall health status.
Bottom line: Don't take vitamin D to prevent cancer or heart disease — VITAL closed this question for primary prevention.
How it works
How to take it
What to track
Bottom line: 600–2,000 IU daily with a fatty meal covers most adults. Get a 25(OH)D test if you're planning anything above 2,000 IU/day or have malabsorption / chronic disease.
4 commercial forms
Compare the main delivery options and what they’re best suited for.
Vitamin D3 (cholecalciferol)
PreferredThe form your skin makes from sunlight and the one used in most supplements. Multiple comparative trials show D3 raises and maintains serum 25(OH)D more effectively than D2 at the same dose, especially with intermittent dosing.
Most effective form for raising serum 25(OH)D.
Vitamin D2 (ergocalciferol)
Plant-derivedProduced from fungi/yeast under UV light. Used in some prescription products (often 50,000 IU capsules for deficiency repletion) and in vegan supplements. Effective for treating deficiency but raises 25(OH)D less and for shorter duration than D3.
Adequate but less efficient than D3.
Calcitriol (1,25-dihydroxyvitamin D)
PrescriptionThe active hormone form, prescribed for chronic kidney disease, hypoparathyroidism, and rare disorders of vitamin D activation. Skips the kidney-activation step. Narrow therapeutic window — requires medical supervision and serum calcium monitoring.
Pharmacologically active; prescription only.
Calcifediol (25-hydroxyvitamin D3)
Faster actingSkips the liver hydroxylation step, raising serum 25(OH)D faster than D3. Available as a prescription (Rayaldee) for secondary hyperparathyroidism in CKD; some OTC products exist outside the US. Useful when rapid repletion matters; standard D3 is fine for routine use.
Faster onset than D3; not commonly needed.
Safety
Know the common side effects, key cautions, and who should avoid it.
Common side effects
Serious risks
Hypercalcemia from chronic intake above 10,000 IU/day — symptoms include nausea, vomiting, weakness, frequent urination; severe cases cause kidney stones, kidney damage, or cardiac arrhythmias. Vitamin D from sun or food does not cause toxicity.
Hypercalciuria and kidney stones with combined high-dose vitamin D + calcium supplementation (especially in older adults).
Who should avoid it
- People with sarcoidosis, tuberculosis, lymphoma, or other granulomatous diseases — these can cause unregulated vitamin D activation, leading to hypercalcemia even at normal doses.
- People with primary hyperparathyroidism or pre-existing hypercalcemia — needs endocrinology guidance.
- People with severe kidney disease (CKD stage 4–5) — vitamin D metabolism is impaired and active forms (calcitriol) are usually preferred under nephrologist guidance.
Pregnancy & breastfeeding
Pregnancy and lactation RDA is 15 mcg (600 IU)/day; UL is 100 mcg (4,000 IU)/day. The 600 IU dose is generally found in standard prenatals and is safe. 27 case reports of in-utero exposure to serum 25(OH)D >125 nmol/L did not show increased birth defect risk. High doses above the UL haven't been adequately studied in pregnancy — discuss with your obstetrician before exceeding 4,000 IU/day. Breast milk contains vitamin D in modest amounts; the AAP recommends supplementing the breastfed infant with 400 IU/day directly.
Bottom line: Doses up to 4,000 IU/day are safe for most adults long-term. Get blood testing before going higher; certain medical conditions need specialist input regardless of dose.
Interactions
Orlistat reduces dietary fat absorption and with it vitamin D absorption. Separate dosing by at least 2 hours and consider monitoring 25(OH)D periodically.
Thiazides reduce urinary calcium loss; combined with vitamin D (and especially calcium) supplements they can cause hypercalcemia, particularly in older adults or those with kidney impairment.
Long-term steroids reduce calcium absorption and impair vitamin D metabolism, increasing the risk of osteoporosis. Higher vitamin D + calcium intake is usually recommended during chronic steroid therapy.
Reduce vitamin D absorption from the gut. Take vitamin D at least 1 hour before or 4 hours after the sequestrant.
Induce hepatic enzymes that accelerate vitamin D breakdown — chronic users often need higher vitamin D intake to maintain adequate 25(OH)D.
Vitamin D and atorvastatin compete for CYP3A4 metabolism; concurrent vitamin D may reduce atorvastatin levels modestly. Generally safe to combine; mention to your prescriber.
Vitamin D increases gut calcium absorption — combining high-dose vitamin D with calcium raises hypercalcemia / kidney stone risk, especially in older adults. Calcium alone or with modest vitamin D is preferred.
Documented interactions
Evidence-graded pair pages with sources, dosing notes, and timing guidance — a complement to the narrative section above.
Warnings (9)
+ phenobarbital
highPhenobarbital is a strong inducer of liver enzymes that speed the breakdown of vitamin D, so long-term use can lower 25-hydroxyvitamin D and, over months to years, contribute to softened bones (osteomalacia in adults, rickets in children) and higher fracture risk. Children and older or housebound adults are most vulnerable. The drop in vitamin D is well documented; some experimental work also suggests phenobarbital may slow vitamin D activation, though that mechanism rests on animal and cell studies. Have vitamin D and bone-related labs reviewed and discuss ongoing vitamin D with your doctor or pharmacist.
+ phenytoin
highPhenytoin induces the liver enzymes that break down vitamin D, accelerating clearance of 25-hydroxyvitamin D and lowering circulating levels over time. The downstream result can be reduced calcium absorption, a compensatory rise in parathyroid hormone, and an increased risk of softened bones (osteomalacia) and fractures with long-term use.
+ carbamazepine
highCarbamazepine activates the pregnane X receptor and induces the liver enzymes (including CYP3A4 and CYP24A1) that break down vitamin D, accelerating the clearance of 25-hydroxyvitamin D into inactive metabolites. A meta-analysis and observational studies consistently show lower 25(OH)D in long-term carbamazepine users, along with a secondary-hyperparathyroidism pattern and reduced bone density that raises fracture risk over years of therapy.
+ prednisone
moderateGlucocorticoids such as prednisone speed up the breakdown of vitamin D and blunt vitamin D-driven calcium absorption at the gut, which contributes to bone loss. Population data link oral steroid use to a higher rate of severe vitamin D deficiency, so vitamin D plus adequate calcium is a standard part of long-term steroid care.
Beneficial pairs (4)
+ magnesium
synergyMagnesium helps activate and support the function of vitamin D; low magnesium can reduce the effectiveness of vitamin D supplementation. This is a beneficial nutrient synergy rather than a harmful interaction.
+ vitamin k2
synergyVitamin D and vitamin K2 act synergistically on calcium metabolism: vitamin D increases calcium absorption while vitamin K2 activates osteocalcin and matrix Gla protein to direct calcium into bone and away from soft tissue. The main caution is for people taking warfarin.
+ omega-3
synergyFat from omega-3 supports absorption of the fat-soluble vitamin D
+ probiotics
synergyVitamin D and probiotics act on overlapping pathways in the gut. Vitamin D supports vitamin D receptor (VDR) activity in the intestinal lining, which probiotics rely on for their anti-inflammatory and barrier-strengthening effects, while some probiotic strains appear to modestly raise circulating vitamin D. Randomized trials suggest combined supplementation can outperform either alone for some inflammatory and gut-barrier endpoints, though the evidence base is still limited.
Protocols featuring Vitamin D
Evidence-backed routines where Vitamin D plays a role.
Daily Essentials — Foundation
general
Before any goal-specific protocol, most adults benefit from filling four common nutritional gaps: vitamin D3, magnesium, omega-3 EPA/DHA, and a basic multivitamin. These four cover the deficiencies that affect everything else — sleep, mood, immune function, energy, cognitive performance, and long-term cardiovascular and skeletal health. If you''re going to take only ONE protocol from Pilora, this is it. It''s the universal foundation. Everything else (Better Sleep, Daily Calm, Foundational Longevity, etc.) layers on top of this baseline. The framing here is unglamorous. There''s no novelty, no proprietary blend, no Instagram trend. Just the four supplements with the most consistent long-term human evidence for general health support.
Statin Companion
medication
Statins are the most-evidenced cardiovascular medication ever invented — they prevent heart attacks, strokes, and cardiovascular death across multiple massive trials. They''re also the most widely-prescribed class of medication in adults over 40. The catch: statins inhibit HMG-CoA reductase, the enzyme that produces cholesterol — but the SAME pathway also produces CoQ10 and dolichols. As a result, statin users show 19-54% reductions in serum CoQ10 in trials, and CoQ10 depletion is implicated in statin-associated muscle symptoms (the most common reason patients discontinue statins). Vitamin D status independently affects statin tolerance. Omega-3 complements statin lipid management. This protocol is for adults ACTIVELY on a statin medication (atorvastatin/Lipitor, rosuvastatin/Crestor, simvastatin/Zocor, pravastatin, etc.). The goal: mitigate side effects, support muscle and energy, complement cardiovascular protection. CRITICAL: this protocol does NOT replace your statin. Statins prevent cardiovascular events; the supplements address downstream effects. If you''re experiencing statin-related muscle symptoms, talk to your cardiologist or PCP. Options include CoQ10 supplementation, switching statin type, lowering dose, alternative-day dosing, or in rare cases switching medication class entirely. Don''t stop your statin without medical guidance.
PCOS Support
hormones
Polycystic ovary syndrome (PCOS) affects roughly 10% of reproductive-age women and is one of the most under-diagnosed endocrine conditions. The core pathology involves insulin resistance, androgen excess, and ovulatory dysfunction — and the supplement category here has unusually good evidence. Myo-inositol is the gold-standard supplemental intervention for PCOS, with effects approaching metformin for restoring ovulation and reducing hyperandrogenism. NAC has small but consistent evidence for ovulation and insulin sensitivity. Vitamin D, magnesium, and berberine support the underlying insulin-resistance pathway. This stack complements lifestyle (the most impactful intervention) and medical therapy when needed. It does NOT replace metformin, GLP-1 agonists, or ovulation induction in women actively trying to conceive — but it can reduce reliance on them in milder cases.
Women's Essentials 30-50
general
The decade between 30 and 50 is when women navigate the most physiologically diverse stretch of adult life: menstruation, possibly pregnancy and postpartum, and the start of perimenopause. The everyday nutritional needs cover iron (menstruation), folate (preconception or peri-pregnancy), vitamin D, magnesium, omega-3, and a B-complex. Bone density also begins its first measurable decline, making early attention to vitamin D and weight-bearing exercise especially leveraged. This protocol is calibrated for women in this window — layer goal-specific protocols (PMS Support, Perimenopause Support, Fertility Prep, Postpartum Support, Hair Loss, Bone Density) on top as life stage requires.
Men's Essentials 30-50
general
The decade between 30 and 50 is when men start to drift from "automatic health" into actively maintained health. Testosterone declines ~1% per year starting around 30, cardiovascular risk markers begin shifting, lean muscle mass starts to decrease without active training, and small recovery imbalances accumulate. This protocol is the everyday foundation specifically calibrated for men in this window: vitamin D, magnesium, omega-3, zinc, and CoQ10. Each addresses a relevant pathway — testosterone synthesis, cardiovascular protection, sleep and stress, mitochondrial energy. Layer goal-specific protocols (Testosterone Support, Foundational Longevity, Joint Health) on top of this baseline as needed.
Hair Loss Support — Men
beauty
Male pattern hair loss (androgenetic alopecia) affects roughly 50% of men by age 50 and is primarily driven by dihydrotestosterone (DHT) sensitivity in genetically predisposed hair follicles. The gold-standard pharmaceutical interventions are topical minoxidil (Rogaine) and oral finasteride — both with the strongest trial evidence of any hair-loss treatment available. The supplement category here is complementary: saw palmetto modestly inhibits 5-alpha-reductase (the same enzyme finasteride targets), pumpkin seed oil has small trial evidence for hair count improvement, and zinc plus vitamin D address commonly low cofactors. None of these match minoxidil/finasteride effect sizes — they''re for adults who prefer a supplement-first approach, can''t tolerate finasteride side effects, or want to stack on top of pharmaceuticals. If hair loss is patchy, sudden, accompanied by scalp pain or scarring — see a dermatologist. Those patterns aren''t androgenetic alopecia and require different treatment.
SSRI / Antidepressant Companion
medication
Selective serotonin reuptake inhibitors (sertraline/Zoloft, escitalopram/Lexapro, fluoxetine/Prozac, paroxetine/Paxil, citalopram/Celexa) and SNRIs (venlafaxine/Effexor, duloxetine/Cymbalta) are first-line pharmaceutical antidepressants with strong evidence for moderate-to-severe depression and anxiety disorders. The supplement category here is meaningfully different from Mood & Mild Depression — this is for adults ALREADY on antidepressants, where the goal is augmentation (improving response or reducing residual symptoms), addressing common SSRI side effects, and supporting overall mental health alongside medication. CRITICAL: Several supplements with serotonergic activity (5-HTP, SAMe, saffron, St. John''s Wort, tryptophan) CANNOT be combined with SSRIs/SNRIs due to serotonin syndrome risk. This protocol uses NON-serotonergic supplements that are safe to combine: omega-3 (augmentation evidence), B-complex (mood support), vitamin D (commonly deficient in depressed patients), magnesium (anxiety, sleep, side effects). If you''re considering stopping antidepressants, talk to your prescriber and taper appropriately. Sudden discontinuation causes withdrawal symptoms (especially with paroxetine and venlafaxine). Don''t self-discontinue.
Daily Immune Foundation
immunity
Year-round immune support is mostly about correcting common nutrient gaps rather than "boosting" immunity (a misleading framing — you can''t make a healthy immune system more reactive without causing autoimmune problems). The four supplements with the strongest evidence for general immune support are vitamin D3 (the single most-evidenced supplement for respiratory infection prevention in deficient adults), zinc, vitamin C (modest cold-prevention effect), and quercetin (mast cell modulation + general antiviral activity in vitro). This stack is for daily use during cold/flu season, in immunocompromising situations (heavy training, chronic stress, frequent travel), or as preventive maintenance. For acute cold/flu treatment, see Cold/Flu Recovery (Acute). The most-leveraged immune intervention is sleep, not supplementation. A single night of poor sleep reduces natural killer cell activity by ~70%.
Mood & Mild Depression
mood
Depression and anxiety are biologically related but mechanistically distinct — Anxiety Relief targets the over-activation pattern; this protocol targets the low-mood, anhedonia, and energy-depletion pattern of mild-to-moderate depression. The supplement category for depression has more rigorous evidence than most realize: SAMe (S-adenosyl methionine) has trial evidence comparable to some SSRIs for mild-to-moderate depression; high-EPA omega-3 has multiple meta-analyses supporting effect; saffron has Iranian and Australian trial evidence comparable to fluoxetine in some studies; vitamin D supplementation reduces depressive symptoms in deficient adults. CRITICAL: This protocol is for MILD-TO-MODERATE depression in adults who are NOT currently in crisis. If you have thoughts of self-harm or suicide, severe symptoms disrupting daily function, or have not improved with conservative measures — please see a mental health professional. SSRIs, SNRIs, and psychotherapy have far larger effect sizes than supplements for moderate-to-severe disease. This is NOT a substitute for proper psychiatric care. If you''re currently taking an antidepressant and want to add supplements, coordinate with your prescriber. Several items below have serotonergic activity that compounds with SSRIs/MAOIs.
Healthy Aging 60+
senior
Healthy aging is not about frailty management — it''s about preserving function, independence, and quality of life into the 70s, 80s, and beyond. The physiology of 60+ adults is genuinely different from younger adults: B12 absorption declines (~10-30% have impaired absorption due to reduced gastric acid), skin vitamin D synthesis drops by ~50% relative to 30-year-olds, anabolic resistance means older muscles need more protein to maintain mass, bone density loss accelerates (especially in postmenopausal women), and chronic disease burden rises. The good news: every one of these is addressable with the right combination of nutrition, training, and targeted supplementation. The strongest predictor of healthy aging is not genetics — it''s grip strength, gait speed, and cardiovascular fitness. This is the FOUNDATION protocol for adults 60+ — distinct from Foundational Longevity (broad-age longevity foundation) and Daily Essentials (general adult). Six core supplements that address the documented physiological changes of aging. Layer disease-specific protocols (Bone Density Support, Sarcopenia, Cardiovascular protocols, Cognitive Aging) on top of this baseline. The biggest single intervention available to older adults is resistance training. No supplement combination compensates for sedentary aging. Strength training 2-3× per week preserves muscle mass, bone density, and metabolic function more than any nutritional intervention.
Food sources
| Food | Amount | %DV |
|---|---|---|
| Cod liver oil | 1 Tbsp (34 mcg / 1,360 IU) | 170% |
| Trout, farmed, cooked | 3 oz (16.2 mcg / 645 IU) | 81% |
| Salmon (sockeye), cooked | 3 oz (14.2 mcg / 570 IU) | 71% |
| Mushrooms (UV-exposed) | ½ cup (9.2 mcg / 366 IU) | 46% |
| Milk, 2% fortified | 1 cup (2.9 mcg / 120 IU) | 15% |
| Soy milk, fortified | 1 cup (2.5 mcg / 100 IU) | 13% |
| Orange juice, fortified | 1 cup (2.5 mcg / 100 IU) | 13% |
| Sardines, canned in oil | 2 sardines (1.2 mcg / 46 IU) | 6% |
| Egg, large (yolk has the D) | 1 egg (1.1 mcg / 44 IU) | 6% |
| Tuna, canned in water | 3 oz (1.0 mcg / 40 IU) | 5% |
| Beef liver, braised | 3 oz (1.0 mcg / 42 IU) | 5% |
| Cheddar cheese | 1.5 oz (0.4 mcg / 17 IU) | 2% |
Cod liver oil
- Amount
- 1 Tbsp (34 mcg / 1,360 IU)
- %DV
- 170%
Trout, farmed, cooked
- Amount
- 3 oz (16.2 mcg / 645 IU)
- %DV
- 81%
Salmon (sockeye), cooked
- Amount
- 3 oz (14.2 mcg / 570 IU)
- %DV
- 71%
Mushrooms (UV-exposed)
- Amount
- ½ cup (9.2 mcg / 366 IU)
- %DV
- 46%
Milk, 2% fortified
- Amount
- 1 cup (2.9 mcg / 120 IU)
- %DV
- 15%
Soy milk, fortified
- Amount
- 1 cup (2.5 mcg / 100 IU)
- %DV
- 13%
Orange juice, fortified
- Amount
- 1 cup (2.5 mcg / 100 IU)
- %DV
- 13%
Sardines, canned in oil
- Amount
- 2 sardines (1.2 mcg / 46 IU)
- %DV
- 6%
Egg, large (yolk has the D)
- Amount
- 1 egg (1.1 mcg / 44 IU)
- %DV
- 6%
Tuna, canned in water
- Amount
- 3 oz (1.0 mcg / 40 IU)
- %DV
- 5%
Beef liver, braised
- Amount
- 3 oz (1.0 mcg / 42 IU)
- %DV
- 5%
Cheddar cheese
- Amount
- 1.5 oz (0.4 mcg / 17 IU)
- %DV
- 2%
Choosing a product
What to look for on the label — and what to be skeptical of.
Look for…
Be skeptical of…
Frequently asked questions
How much vitamin D should I take per day?⌄
Most adults do well on 1,000 to 2,000 IU per day from supplements, which complements typical food and sun exposure. People with documented deficiency may need more under a doctor's supervision.
Should I take vitamin D with food?⌄
Yes. Vitamin D absorbs significantly better when taken with a meal that contains some fat. The fat does not need to be large — a regular meal works fine.
What is the difference between vitamin D2 and D3?⌄
D3 (cholecalciferol) comes from animal sources or sunlight on skin, while D2 (ergocalciferol) comes from plants and fungi. D3 generally raises blood levels more effectively than D2.
Can I get enough vitamin D from sunlight?⌄
Maybe, depending on where you live, your skin tone, and how much time you spend outside. People at higher latitudes, with darker skin, or who cover up when outside often need supplements, especially in winter.
How do I know if I am deficient?⌄
A blood test measuring serum 25-hydroxyvitamin D is the standard. Levels below 30 nmol/L (12 ng/mL) indicate deficiency; 50 nmol/L (20 ng/mL) or higher is considered sufficient for most people.
References by claim
Prevention of rickets and osteomalacia
NIH Office of Dietary Supplements — Vitamin D — Health Professional Fact Sheet (2024) link
Cancer / cardiovascular event prevention
Manson et al., 2019 (VITAL) — PubMed — New England Journal of Medicine (2019) link
Fracture prevention (non-deficient adults)
LeBoff et al., 2022 (VITAL Fractures) — PubMed — New England Journal of Medicine (2022) link
Acute respiratory tract infections (deficient adults)
All-cause mortality (older adults)
Bjelakovic et al., 2014 (Cochrane) — PubMed — Cochrane Database of Systematic Reviews (2014) link
Falls in community-dwelling older adults
USPSTF 2024 Draft Recommendation — U.S. Preventive Services Task Force (2024) link
Safety
MotherToBaby Vitamin D Fact Sheet — OTIS (2024) link
Track Vitamin D with Pilora
Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.
Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.