Lots of one form of Vitamin D from wild animal organs

The hidden vitamin D in wild game: what organs, meat, and sun meant for Native Americans

Traditional Native Americans likely obtained 200-1,000+ IU of effective daily vitamin D activity from wild game meat and organs alone — modest by modern supplementation standards, but significantly amplified by the 25(OH)D content concentrated in organ meats. The bioavailability multiplier of 25(OH)D (calcifediol) over vitamin D3 — estimated at 3-5x in most studies — means that even small amounts of 25(OH)D in liver and kidney tissue carried outsized nutritional impact. Yet the dominant vitamin D source for most tribes was almost certainly cutaneous synthesis from sun exposure, not diet. A critical finding: published measurements of vitamin D in wild terrestrial game are shockingly sparse, and the few that exist show lower values than many researchers have assumed.

Wild game meat contains far less vitamin D than expected

The single most important dataset comes from Phillips, Pehrsson & Patterson (2018), who used validated UPLC-MS to measure both vitamin D3 and 25(OH)D3 in traditional Native Alaskan foods. Their results for wild caribou — the closest measured proxy for wild cervids like deer and elk — were striking:

Caribou tissue	Vitamin D3 (pg/100 g)	25(OH)D3 (pg/100 g)
Ground, raw	<0.1	<0.1
Hind quarter, raw	<0.1	<0.1
Flesh, boiled	<0.1	<0.1
Meat, dried	<0.1	0.024

Wild goose similarly showed <0.1 pg D3 and only 0.028-0.037 pg 25(OH)D3 per 100 g. (scienceDirect +2) The USDA FoodData Central lists 0 pg vitamin D for bison, bear, deer, elk, and moose — though these zeros likely reflect unmeasured rather than confirmed-absent values. No published study has ever measured 25(OH)D3 in wild deer liver, wild bison kidney, or any wild game organ tissue. This is the single largest data gap in this entire field.

The explanation for these low values involves biology: wild terrestrial mammals synthesize vitamin D3 in their skin via UVB, but thick hides, fur, and high-latitude habitats limit cutaneous synthesis. The Phillips caribou samples came from Alaska, where UVB availability is minimal. Wild bison grazing the Great Plains at latitudes 35-50°N would have received substantially more UVB, but no one has measured the result.

For comparison, marine mammals from the same Phillips study contained orders of magnitude more vitamin D: beluga whale dried meat had 2.01 pg D3 and 0.986 pg 25(OH)D3 per 100 g, (vt) (scienceDirect) and seal oils reached 16-29 pg D3/100 g.

(sdenceDirect +2) The marine food chain concentrates vitamin D in ways the terrestrial food chain does not.

Organ meats concentrate 25(OH)D at 3-10x the level found in muscle

While wild game organ data is absent, domesticated bovine tissue data from multiple studies (Schmid & Walther 2013; Jakobsen & Christensen 2021; Koshy & VanDerSlik 1977; Montgomery et al. 2000-2004) establishes a clear tissue hierarchy for 25(OH)D3 concentration:

Bovine tissue	D3 range (pg/100 g)	25(OH)D3 range (pg/100 g)
Kidney	0.13-2.71	0.09-2.33
Liver	0.19-1.42	0.07-0.77
Muscle	0.08-0.41	0.08-0.58

The pattern kidney > liver > muscle is consistent across studies and reflects the biology of vitamin D metabolism: the liver hydroxylates D3 into 25(OH)D3 (concentrating it there), while the kidney performs the second hydroxylation to active l,25(OH)₂D3.

(pubMed central+2) Jakobsen (2021) reported calf liver at 0.533 pg 25(OH)D3/100 g (pubMed central) — roughly 3.5x the level in veal muscle (0.15 pg). Montgomery et al. (2000) found beef kidney at 2.33 pg 25(OH)D3/100 g, (PubMed central) some 17x higher than muscle tissue in the same animals, (nih)

In free-range pigs (the best available model for outdoor-living animals), skin contained 1.11 pg 25(OH)D3/100 g, subcutaneous fat 0.63 pg, and lean meat 0.38 pg (nih) — establishing that fat and skin also serve as important 25(OH)D reservoirs. Veal was found to be >91% 25(OH)D3 by vitamin D form, meaning nearly all its vitamin D activity comes from the metabolite rather than parent D3. (nih)

These domesticated-animal values represent the best available proxy for what wild game organs might contain. Wild bison kidney and liver, from animals spending their entire lives outdoors at Great Plains latitudes, may have contained equal or higher 25(OH)D3 concentrations — but this remains speculative without direct measurements.

The 25(OH)D potency multiplier: 3-5¹ in most contexts, not a fixed 5¹

The commonly cited "5x more potent" figure traces to Cashman et al. (2012), a randomized controlled trial in older adults during winter. Each microgram of oral 25(OH)D3 raised serum 25(OH)D by 4.77 nmol/L, versus 0.96 nmol/L per microgram of D3 — a 5.0x ratio at the 20 pg dose. (scienceDirect) But the multiplier is dose- and baseline-dependent:

Study	Year	Multiplier	Context
Stamp et al.	1977	~10x	High therapeutic doses
Bouillon (high baseline)	2023	6-8x	Higher serum 25(OH)D at start
Shieh et al.	2017	-5.5X	Multiethnic, deficient adults
Cashman et al.	2012	S.Ox	20 pg dose, older adults, winter
Cashman et al.	2012	4.2x	7 pg dose
P6rez-Castrill6n	2021	3.8X	Postmenopausal, deficient
Bischoff-Ferrari	2012	-3.4X	Postmenopausal women
Bouillon meta-analysis	2018	3.2x	9 RCTs, ^25 pg/day
EFSA official factor	2023	2.5 x	Regulatory/labelling
Rossini et al.	-2016	1.66X	Lowest reported

The mechanism: 25(OH)D bypasses the rate-limiting hepatic hydroxylation step, (Medscape+3) is absorbed via the portal vein rather than the lymphatic system (achieving near-100% absorption), and is less sequestered in adipose tissue than parent D3. (Nature+2) At low dietary doses typical of food intake, a multiplier of 3-5x is the best-supported range. EFSA's conservative 2.5x factor is used for food labelling. (niP) (wiiey online Library)

For calculating "total vitamin D activity" from foods: Total activity = vitamin D3 + (25(OH)D3 x conversion factor). Using this formula, Jakobsen & Christensen (2021) found that 25(OH)D3 contributed 18-24% of total dietary vitamin D activity in Danish diets — a substantial fraction from a metabolite most food databases still ignore. (PubMed central) (nlh)

Plains and Woodland Indians consumed every organ, liver first

The ethnographic and historical record on organ consumption is extensive and unambiguous. Virtually every edible organ was consumed across Plains, Woodland, and Subarctic tribes. (Frontier Life)

The liver held special status. Among the Lakota, Comanche, Blackfoot, and other Plains tribes, raw liver dipped in bile was eaten immediately at the kill site — one of the most consistently documented practices across the ethnographic record. (Tribevitamins) A Lakota elder from Wambli, South Dakota recalled how "his father and uncles ate raw liver after smearing bile on it." (LakotaTimes-) The Comanche "sometimes ate raw meat, especially raw liver flavored with gall" (S.C. Gwynne, Empire of the Summer Moon). (Meatrition) Beverly Hungry Wolfs The Ways of My Grandmothers describes Blackfoot women roasting, baking, or sun-drying hearts, kidneys, and liver; slicing and drying lungs; eating brains raw; and preparing blood mixed with dried roots. (Weston A. Price Foundation) (westonaprice)

Beyond liver, documented organ consumption included:

• Kidney: eaten raw at the kill site; given to ailing tribe members (Notes from the Frontier)

• Heart: considered a trophy part; ( Nativeamericannetroots) roasted or boiled

• Tongue: universally regarded as the greatest delicacy; served ceremonially at the Sun Dance (westonaprice)

• Brain: eaten raw; also used for tanning hides

• Bone marrow: femur bones cracked open and marrow consumed raw

(Nativeamericannetroots) ^{2 1}

Consumption quantities were enormous. Lewis and Clark documented 9 pounds of meat per person per day among their expedition members eating like Plains Indians, (pbs+3) Ethnographic estimates suggest active Plains hunters consumed 1-1.5 kg (2.2-3.3 lbs) of total meat, organs, and fat daily, with 76-85% of total calories from animal sources (Cordain, from the Ethnographic Atlas). During periods of abundance, this could reach 3-4 kg.

Estimated daily vitamin D from a traditional wild game diet

Calculating dietary vitamin D intake requires navigating a minefield of missing data. No study has directly measured vitamin D in wild bison, deer, or elk organs. The best we can do is construct scenarios using the available proxies.

Scenario 1 — Conservative (using wild caribou muscle data + domestic cattle organ data):

Assumes 600 g muscle +100 g liver + 50 g kidney daily:

Component	D3(pg)	25(OH)D3(pg)	25(OH)D3 X 4 (effective pg)	Total activity (pg)
Muscle, 600 g	~0.6	-0.6	2.4	3.0
Liver, 100 g	-0.5	-0.4	1.6	2.1
Kidney, 50 g	-0.4	-0.5	2.0	2.4
Daily total	-1.5	-1.5	6.0	-7.5 pg (300IU)

Scenario 2 — Moderate (using outdoor-raised cattle proxy, higher organ intake):

Assumes 800 g muscle +150 g liver + 75 g kidney, with 2x multiplier for wild/outdoor animals:

Component	D3(pg)	25(OH)D3(pg)	25(OH)D3 x 5 (effective pg)	Total activity (pg)
Muscle, 800 g	-1.6	-2.4	12.0	13.6
Liver, 150 g	-2.0	-1.2	6.0	8.0
Kidney, 75 g	-1.5	-1.5	7.5	9.0
Daily total	-5.1	-5.1	25.5	-30.6 pg (1,224 IU)

Scenario 3 — Generous (high meat consumption, free-range pig model extrapolation):

Using the 6-10x vitamin D difference observed between free-range and indoor pigs as a proxy for wild versus domestic differences, and assuming heavy consumption days (feasting after a kill):

Estimated total vitamin D activity: -40-60 pg/day (1,600-2,400 IU)

The realistic range across all scenarios is approximately 300-1,500 IU/day of effective vitamin D activity from diet alone, with the majority coming from 25(OH)D3 in organ meats rather than parent D3 in muscle tissue. This is 2-10x the modern American dietary intake of -160-200 IU/day, (office of Dietary suppiem... ) but still below the -4,000 IU/day Vieth estimates is needed to maintain ancestral serum levels of -115 nmol/L without sun.

Sun exposure, not diet, was the primary vitamin D source

The dietary estimates above point to an inescapable conclusion: sun exposure was the dominant vitamin D source for most Native American populations. Reinhold Vieth (1999, 2003,2006,2020) has argued that early humans in sun-rich environments maintained serum 25(OH)D concentrations of -115 nmol/L (46 ng/mL), (pubMed) consistent with the Luxwolda et al. (2012) measurements of Maasai pastoralists (mean 119 nmol/L) and Hadza hunter-gatherers (mean 109 nmol/L) in East Africa — both groups with low fish intake, confirming sun as the primary driver. (Cambridge core)

For Plains Indians at latitudes 35-50°N, full-body sun exposure during warm months (March-October) would have provided an estimated 4,000-10,000 IU/day equivalent. Combined with dietary intake of300-1,500 IU, a summer total of5,000-11,000 IU/day is plausible — more than sufficient to maintain serum 25(OH)D above 100 nmol/L.

Winter presented the real challenge. Above ~40°N, cutaneous vitamin D synthesis effectively ceases from November through February. (Wikipedia) With only dietary vitamin D available (300-1,500 IU/day from stored pemmican, dried meats, and any fresh game), serum 25(OH)D would have declined through winter, buffered partly by body stores (25(OH)D half-life -2 months) and possibly by genetic adaptations. Pre-Columbian skeletal evidence shows virtually no rickets among Native American populations, and a 1942 medical survey found no rickets cases among northern Manitoba Indians living above 55°N despite minimal marine food access (Taylor & Francis) — suggesting biological accommodations including VDR polymorphisms and enhanced vitamin D conversion efficiency. ( ResearchGate)

The Yup'ik Eskimos of Alaska, whose traditional diet is marine-heavy, achieved mean serum 25(OH)D of 95.6 nmol/L (38 ng/mL) (PubMed central) (Discover Magazine) with dietary vitamin D of604 ± 808 IU/day (PubMed central) — demonstrating that a marine-based traditional diet, rich in fish and seal oil, could sustain near-adequate vitamin D status even at extreme latitudes where sun exposure contributes little.

Conclusion: what the data reveals and what remains unknown

The total vitamin D picture for traditional Native American diets rests on a foundation of surprisingly thin analytical data. Not a single published study has measured 25(OH)D3 in wild deer liver, bison kidney, elk heart, or any wild game organ. The estimates presented here extrapolate from domesticated cattle organ data and the lone wild caribou muscle dataset from Phillips et al. (2018). This represents a genuine opportunity for future research — particularly for Vitamin D Life content highlighting the gap between assumed and measured values.

What the evidence does support: organ meats, especially kidney and liver, concentrate 25(OH)D3 at 3-17x the level in muscle meat. (PubMed central) (PubMed) With the 25(OH)D bioavailability multiplier of 3-5x, (Creighton university) organ consumption substantially amplified effective vitamin D intake beyond what muscle meat alone provided. Native Americans' universal practice of prioritizing organ consumption — eating liver and kidney raw at the kill site, reserving muscle meat as secondary (Wikipedia) (Frontier Life) — inadvertently maximized their dietary vitamin D activity from terrestrial game.

(PubMed Central) (MDPl)

But even with generous organ consumption, dietary vitamin D from wild terrestrial game likely provided only 300-1,500 IU/day of effective activity — enough to exceed the modern RDA of600IU, but insufficient alone to explain the apparent absence of vitamin D deficiency in pre-contact populations. The remaining gap was filled by sun exposure (dominant source, -4,000-10,000 IU/day in summer), (The Globe and Mail) marine foods where available (potentially thousands of IU/day from fish, seal oil, and whale), (sdenceDirect) (ResearchGate) and likely genetic and metabolic adaptations that reduced vitamin D requirements in northern Indigenous peoples. (PubMed central) The story of vitamin D in traditional Native American diets is ultimately a story about the whole system — sun, organs, marine fat, and biology working together — not any single dietary component.

Adrenal glands: cut up and shared communally; recognized as preventing scurvy (Weston A. Price documentation among Canadian tribes) (Weston a. Price Foundation) (westonaprice)

Among Subarctic tribes, muscle meat was sometimes fed to dogs while organs were reserved for human consumption. (Nahia Earth) Samuel Hearne (1768) documented caribou "beeatee" — a haggis-like dish of blood, fat, heart, and lungs cooked in the stomach casing. (westonaprice) The Chippewa and Cree fermented blood mixed with semi-digested stomach contents, (westonaprice)

• Intestines: stuffed with meat and roasted (Blackfoot "Sapotsis"); dried; or consumed

in Competitive eating (Weston A. Price Foundation) (westonaprice)

• Blood: collected (1.5-2 gallons per bison) for soups; (Notes from the Frontier)used in sacred Holy Smoke ceremonies (westonaprice)