Functional Nutrition
Root cause nutrition. Personalized to you.
Work with Cristina Terwilliger RN, our functional nutritionist, to uncover the underlying causes of your symptoms through advanced testing and individualized nutrition strategies. Not a diet plan — a complete picture of your health.
$100/mo
after initial workup
Initial workup fee varies based on the depth of your assessment
Cristina Terwilliger, RN
Functional Nutritionist
Costa MesaA Different Approach
Not a diet. A deeper look.
Most nutritional advice treats everyone the same. Cristina doesn't. She starts by understanding your unique biology — your symptoms, your history, your labs, and your lifestyle — before making a single recommendation.
Through advanced functional testing including GI-MAP gut microbiome analysis, she uncovers the root causes behind your symptoms rather than simply managing them. Whether it's gut health, hormone imbalance, thyroid dysfunction, chronic fatigue, or inflammation — she looks for the why.
Once you're a nutrition member, you get Cristina's direct contact — just like DPC. Text her a question about a food, a grocery list, a recipe, or a symptom. She holds monthly follow-up appointments and is available anytime in between.
Cristina also builds a personalized supplement protocol based on your lab results — not generic recommendations, but specific supplements at therapeutic doses tailored to what your body actually needs. Members receive wholesale pricing on all recommended supplements.
Advanced functional testing
GI-MAP gut microbiome analysis, hormone panels, inflammatory markers, and more — to find what's actually driving your symptoms. Results are used to build your personalized supplement protocol and targeted nutrition plan — specific to your biology, not a generic template.
Direct access, anytime
Text Cristina directly with questions about food, groceries, supplements, or how you're feeling. She's available between appointments.
Monthly follow-ups included
Regular check-ins to review your progress, adjust your plan, and keep you on track toward your health goals.
Who This Is For
If you’ve been told everything is normal but still don’t feel well…
Functional nutrition goes beyond standard lab ranges to find what’s optimal for your body specifically. Cristina works with people who:
Struggle with gut issues
Bloating, IBS, constipation, diarrhea, or food sensitivities that haven't responded to conventional treatment.
Feel chronically fatigued
Persistent tiredness despite normal sleep — often linked to nutrient deficiencies, gut dysfunction, or hormonal imbalance.
Have hormone imbalances
PMS, irregular cycles, perimenopause, thyroid issues, or symptoms your doctor hasn't been able to explain.
Dealing with inflammation
Chronic pain, autoimmune conditions, skin issues, or persistent inflammation that standard treatment hasn't resolved.
Want to optimize their health
Already healthy but want to perform better, age well, and understand your body at a deeper level. Includes personalized nutrition, supplement optimization, and ongoing guidance.
Managing chronic conditions
Diabetes, hypertension, thyroid disorders, or autoimmune conditions where nutrition plays a central role.
Your Journey
What working with Cristina looks like.
01
Initial assessment
Your first visit is a deep dive — your health history, symptoms, diet, lifestyle, and goals. Cristina may order functional testing based on what she finds. Initial workup fee varies based on depth of assessment.
02
Testing & analysis
Advanced functional testing where appropriate — GI-MAP, hormone panels, inflammatory markers, nutrient levels. Results reviewed and explained in detail.
03
Your personalized plan
A nutrition and lifestyle strategy built specifically for your biology, your goals, and your life — including a personalized diet plan, targeted supplement protocol based on your labs, and grocery and meal guidance tailored to your needs. Not a generic protocol.
04
Ongoing support
Monthly follow-up appointments plus direct access anytime. Text Cristina questions about food, supplements, groceries, or how you're feeling between visits.
Your Nutritionist
Meet Cristina Terwilliger, RN.
Cristina Terwilliger came to functional nutrition the way the best practitioners do — through personal experience. After witnessing firsthand how targeted nutrition and lifestyle changes could transform her own health, she made it her mission to help others uncover the root causes behind their symptoms rather than simply managing them.
At Amity Health, Cristina combines advanced functional testing — including GI-MAP gut microbiome analysis — with individualized, science-based nutrition strategies to address digestion, inflammation, hormone and thyroid balance, stress recovery, and immune optimization. Her approach is deeply personal: she takes the time to understand each patient's unique biology, history, and goals, then builds a plan that's sustainable, not just clinical.
If you've been told your labs are "normal" but you still don't feel well, Cristina is the person to see.
Cristina Terwilliger
RN · Functional Nutritionist
“I came to functional nutrition through my own health journey. I know what it feels like to be told your labs are normal when you know something isn’t right.”
— Cristina Terwilliger, RN
Membership Pricing
Simple, transparent pricing.
Functional Nutrition Membership
$100/mo
after your initial workup
Initial workup fee varies based on the depth of your assessment and testing required. Autoimmune protocols and comprehensive functional evaluations require more extensive workups. Contact us to discuss what’s right for you.
Questions about pricing or what to expect? Email us at hello@amityhealthdpc.com
Nutrition members receive exclusive discounts on supplements recommended as part of their personalized protocol.
FAQ
Common questions about functional nutrition.
Ready to start?
Find out what your body has been trying to tell you.
Work with Cristina to uncover the root causes — not just manage the symptoms.
Start Your Nutrition JourneyQuestions? Email hello@amityhealthdpc.com
Cristina Terwilliger, RN
Functional Nutritionist
Costa Mesa Only
1640 Newport Blvd, Suite 440
Costa Mesa, CA 92627
(949) 791-8888
hello@amityhealthdpc.com
Mon–Fri · 9am–4pm