Zest Health Guide to Topical Vitamin D Analogues

Psoriasis causes your skin cells to grow too fast. That rapid overgrowth builds up into the thick, scaly plaques you can see and feel. Topical vitamin D analogues slow that process down. They help your skin cells grow and shed at a more normal pace, which allows plaques to calm and clear over time.

This guide explains how these medications work, how to use them, and what to expect along the way.

What Are Topical Vitamin D Analogues?

Topical vitamin D analogues are prescription medications used primarily to treat psoriasis. Despite the name, they are not the same as vitamin D supplements you take by mouth. They are applied directly to your skin and work locally to slow cell overgrowth and reduce inflammation.

The most common options are calcipotriene, calcitriol, and calcipotriol. Your Zest provider will prescribe the one that fits your situation best.

Before You Begin

A few important things to know before you start:

• Weekly limits matter. Using more than the recommended amount can raise calcium levels in your blood. Stick to the amount your provider prescribes.
• Large body areas. Avoid applying to more than 30 percent of your body surface area.
• Face and skin folds. These medications can cause irritation in delicate areas. Only use there if your provider specifically instructs you to.
• Calcium supplements or high-dose vitamin D. Use with caution if you take these, as the combination may increase the risk of high blood calcium. Talk to your provider if you are unsure.

How to Apply Your Medication

1. Apply a thin layer to affected areas once or twice daily as directed.
2. Gently rub into the skin until absorbed.
3. Wash your hands after applying, unless you are treating your hands.
4. Apply after sun exposure or UV light therapy, not before. Sunlight can make the medication less effective.

Combining With Other Treatments

Vitamin D analogues can be used alone or alongside topical steroids. Combining them is often more effective than using either one on its own. Common strategies your provider may suggest include:

• Vitamin D analogue on weekdays, steroid on weekends
• High-potency steroid in the morning, vitamin D analogue in the evening
• Combination products that contain both in one application
• Vitamin D applied first, followed by a topical steroid for better absorption
• If mixing the two yourself, combine equal parts until a paste forms, then apply to affected areas

How Much to Use

A helpful way to measure your medication is the Fingertip Unit, or FTU. This is the amount of cream squeezed from the tip of your finger to the first crease. One FTU covers roughly the front and back of one adult hand.

General weekly limits to follow:

• Children: up to 50 grams per week
• Adults using calcipotriene: up to 100 grams per week
• Adults using calcitriol: up to 200 grams per week

If you are ever unsure whether you are using the right amount, ask your Zest team. We are always happy to help you calibrate.

Getting Started

Before starting, submit baseline photos of your skin for a severity assessment. No routine blood work is required, but share all current and past medications with your provider.

What to Expect

• Early improvement. You may start to see changes as early as 2 to 4 weeks.
• Maximum benefit. Most people see the best results after 6 to 8 weeks of regular use.
• Best results. These medications work best for mild to moderate psoriasis and are often more effective when combined with topical steroids.
• Long-term use. Regular use can help maintain clear skin over time. Do not stop suddenly when your skin improves. Your provider may want you to continue for maintenance.

Tips for Staying Consistent

• Apply consistently as directed and do not skip applications.
• Use a fragrance-free moisturizer regularly to help with any dryness or irritation.
• Be patient. It can take several weeks to see full results.
• Combining with moisturizers can improve tolerability and reduce irritation.

Safety and Side Effects

Most people tolerate topical vitamin D analogues well. Side effects are generally mild and can include:

• Burning or stinging
• Itching
• Peeling or flaking
• Redness or irritation at the application site

Mild side effects often improve with continued use. A fragrance-free moisturizer can help with dryness. Side effects also tend to be less common with combination steroid and vitamin D products.

These medications are considered safe for children when prescribed and monitored by a provider, and for extended periods when dosing guidelines are followed.

If you are pregnant or planning to become pregnant, talk with your provider. Data on use during pregnancy is limited, and your provider will help you weigh your options.

Rare but Serious Symptoms to Watch For

High calcium levels in the blood, called hypercalcemia, are rare but can occur if you use more than recommended or combine this medication with oral vitamin D supplements. Signs to watch for include:

• Excessive thirst
• Frequent urination
• Nausea
• Confusion

If you notice any of these symptoms, stop using the medication and contact your Zest team right away.

Storing Your Medication

• Store at room temperature
• Keep the tube or bottle tightly closed
• Keep out of reach of children
• Do not ingest
• Check the expiration date before each use

When to Contact Your Zest Team

Reach out if you notice any of the following:

• Severe irritation or burning that does not improve with moisturizers or time
• Signs of a severe allergic reaction or infection
• Unusual worsening redness, pain, swelling, pus, warmth, or fever
• No improvement after 8 weeks of treatment
• Signs of high calcium: excessive thirst, frequent urination, nausea, or confusion

Have more questions? Contact your Zest care team by texting (865) 426-1746 or sending a message from your portal. You've got this, and we've got you.