---
type: source
title: "GLP-1 Users Developing Nutritional Deficiencies at Scale: 12.7% by 6 Months, Vitamin D 13.6% by 12 Months"
author: "IAPAM (American Institute of Anti-Aging Medicine) / Multiple cohort studies"
url: https://iapam.com/glp-1-practice-updates-february-2026
date: 2026-02-01
domain: health
secondary_domains: []
format: report
status: processed
processed_by: vida
processed_date: 2026-04-08
priority: medium
tags: [GLP-1, safety, nutritional-deficiency, vitamin-D, micronutrients, adherence, long-term-effects]
extraction_model: "anthropic/claude-sonnet-4.5"
---

## Content

Large cohort study (n=461,382 GLP-1 users) findings on nutritional deficiency:
- 12.7% of patients had a new nutritional deficiency diagnosis at 6 months of GLP-1 therapy
- By 12 months: vitamin D deficiency reached 13.6%
- Iron, B vitamins, calcium, selenium, and zinc deficiencies rising over time
- Mechanism: GLP-1 suppresses appetite broadly, reducing caloric intake including micronutrient-rich foods

AHA/ACLM/ASN/OMA/TOS joint advisory (American Journal of Clinical Nutrition, 2025): "Nutritional priorities to support GLP-1 therapy for obesity" — first formal multi-society guidance on nutritional monitoring and supplementation for GLP-1 users.

IAPAM clinical practice updates (October 2025, November 2025, February 2026): Practitioners reporting increasing presentation of GLP-1-related nutritional complications including:
- Muscle mass loss (sarcopenia concurrent with fat loss)
- Hair loss (telogen effluvium from protein/micronutrient depletion)
- Bone density concerns with prolonged use

## Agent Notes

**Why this matters:** An underappreciated safety signal at population scale. GLP-1 is being prescribed at unprecedented rates with a fairly simple narrative (inject → lose weight → better health). The nutritional deficiency finding suggests the intervention has second-order health effects that may undermine some of the benefits — particularly for bone health and metabolic function. At 12.7% deficiency rate at 6 months across 461,382 users, this is a public health signal requiring monitoring infrastructure that doesn't currently exist at scale.

**What surprised me:** The magnitude and speed. 12.7% deficiency in 6 months across a half-million people is substantial. This isn't a rare adverse effect — it's a common one. The medical system is deploying this intervention without the monitoring infrastructure to catch and correct the deficiencies. The joint advisory from five major medical societies suggests the field is now taking this seriously, but protocol adoption will lag.

**What I expected but didn't find:** Data on whether digital behavioral support programs (like the Danish cohort) include nutritional monitoring that mitigates deficiency rates. If structured programs prevent deficiencies while standalone prescribing creates them, this is another argument for the behavioral support stack being essential, not optional.

**KB connections:** Connects to the atoms-to-bits argument — if GLP-1 users require nutritional monitoring and supplementation guidance, the software layer (tracking, alerts, dietary coaching) becomes medically necessary, not just an engagement tool. Also connects to the GLP-1 persistence/adherence thread — nutritional deficiency (especially GI discomfort from micronutrient depletion) may contribute to the year-2 dropout cliff.

**Extraction hints:** Primary claim: "GLP-1 receptor agonist therapy produces nutritional deficiencies in 12-14% of users within 6-12 months of initiation, requiring monitoring and supplementation infrastructure that current prescribing practices lack." This is a new claim not in the KB. It complicates the simple "GLP-1 improves health" narrative by introducing a specific population-level safety concern.

**Context:** IAPAM is a practitioner education organization; the cohort study size (461,382) suggests database claims study, likely retrospective. The multi-society joint advisory (AHA/ACLM/ASN/OMA/TOS) in AJCN is high-credibility guidance.

## Curator Notes (structured handoff for extractor)

PRIMARY CONNECTION: GLP-1 agonists largest therapeutic category launch in history; AI drug discovery compresses timelines but doesn't improve clinical failure rate
WHY ARCHIVED: Novel safety signal not currently in KB. Large cohort evidence (n=461k) with multi-society guideline response. Creates a new dimension of the GLP-1 story — it's not just adherence that matters, but the quality of the monitoring infrastructure around it.
EXTRACTION HINT: Scope claim carefully: nutritional deficiency from GLP-1, not general nutritional deficiency. The mechanism (broad appetite suppression reducing micronutrient intake) should be stated explicitly. Flag the monitoring gap as the claim's operational implication.
