GLP-1 - lose Vitamin D, Vitamin C, as well as weight

People on GLP-1s Are Getting an Old-Timey Sailors' Disease

GLP=1 does NOT consume the vitamins

GLP‑1 drugs do not appear to directly deplete vitamin C or other vitamins, but by sharply reducing food intake and altering digestion they can indirectly increase the risk of multiple deficiencies, including vitamin D, B‑12 and others. komonews

What is happening with scurvy?

Reports of scurvy in people taking GLP‑1s (such as Ozempic, Wegovy, Mounjaro) are tied to very low intake of vitamin‑C–rich foods because of appetite suppression, not because the drug chemically destroys vitamin C. wcti12
News and expert commentary emphasize there is no evidence that GLP‑1 medications directly cause scurvy; instead, they reduce appetite and overall intake, so people may simply not eat fruits and vegetables for long periods. kutv

Evidence of broader nutrient deficiencies

A large observational study of >460,000 GLP‑1 users found that about 22% developed at least one nutritional deficiency within 12 months; vitamin D was the most commonly diagnosed deficiency (around 13% by one year). psychologytoday
Other deficiencies reported in GLP‑1 users include vitamin A, vitamin C, several B vitamins, calcium, and zinc, again thought to be largely driven by reduced overall intake and dietary quality, and sometimes by pre‑existing obesity‑related deficiencies. procarenow

Mechanisms relevant to vitamin D

GLP‑1 agonists markedly reduce appetite and caloric intake, leading some patients to eat far less dairy, fatty fish, or fortified foods that supply vitamin D and calcium. westmorelandpharmacy
Many people with obesity already start out vitamin‑D‑deficient, so when intake drops further, measured 25(OH)D levels can fall below diagnostic thresholds, yielding more “new” vitamin D deficiency diagnoses in the first year of GLP‑1 therapy. linkedin
Separate work (in fracture patients, not on drugs) has shown a positive correlation between serum GLP‑1 and vitamin D levels, suggesting overlapping roles in bone metabolism, but this does not show that GLP‑1 agonists themselves lower vitamin D. pmc.ncbi.nlm.nih

B‑12 and absorption‑related issues

GLP‑1 agonists slow gastric emptying and reduce stomach acid, which can theoretically impair absorption of vitamin B‑12 that depends on acid and intrinsic factor, especially in people who already have marginal B‑12 status. healthline
Case reports and reviews describe B‑12 deficiency emerging or being unmasked on semaglutide, prompting some clinicians to co‑prescribe or at least monitor B‑12 in long‑term users. jcimcr

Practical takeaway

Current data support an indirect effect: GLP‑1 drugs drive large, sometimes abrupt reductions in food intake and alter gastric physiology, so deficiencies in vitamin C (scurvy risk), vitamin D, B‑12 and others are more likely if diet and supplements are not adjusted. komonews
For someone on a GLP‑1 medication, reasonable steps are: baseline and periodic labs (25(OH)D, B‑12, possibly vitamin A, folate, iron, zinc), ensuring a nutrient‑dense diet despite smaller portions, and targeted supplementation (particularly vitamin D, vitamin C, B‑12, and calcium) if intake or labs suggest risk. psychologytoday