diff --git a/chrome/content/zotero/xpcom/data/item.js b/chrome/content/zotero/xpcom/data/item.js
index c80df3c129..721b795312 100644
--- a/chrome/content/zotero/xpcom/data/item.js
+++ b/chrome/content/zotero/xpcom/data/item.js
@@ -794,7 +794,30 @@ Zotero.Item.prototype.setField = function (field, value, loadIn) {
 	if (!itemTypeID) {
 		throw new Error('Item type must be set before setting field data');
 	}
-	
+
+	// Loading calls this for every stored value, so use cached field lookups.
+	// Same result as the general path below.
+	if (loadIn && typeof field == 'number') {
+		let info = Zotero.ItemFields._getLoadInfo(itemTypeID, field);
+		if (info && !info.isISBN) {
+			if (field == info.titleID && this.isNote()) {
+				this._noteTitle = value ? value : "";
+				return true;
+			}
+			if (value !== false && !info.valid) {
+				Zotero.debug("'" + field + "' is not a valid field for type '"
+					+ Zotero.ItemTypes.getName(itemTypeID) + "'" + " -- ignoring value '" + value + "'", 2);
+				return false;
+			}
+			if (typeof value == 'string' && !info.multiline
+					&& (value.includes('\n') || value.includes('\r'))) {
+				value = value.replace(/[\r\n]+/g, " ");
+			}
+			this._itemData[info.fieldID] = value;
+			return true;
+		}
+	}
+
 	var fieldID = Zotero.ItemFields.getID(field);
 	if (!fieldID) {
 		throw new Error('"' + field + '" is not a valid itemData field');
diff --git a/chrome/content/zotero/xpcom/data/itemFields.js b/chrome/content/zotero/xpcom/data/itemFields.js
index a9e16e1675..a884fe6dbe 100644
--- a/chrome/content/zotero/xpcom/data/itemFields.js
+++ b/chrome/content/zotero/xpcom/data/itemFields.js
@@ -39,7 +39,9 @@ Zotero.ItemFields = new function () {
 	var _typeFieldNamesByBase = {};
 	var _baseFieldIDsByTypeAndField = {};
 	var _autocompleteFields = null;
-	
+	var _loadInfo = [];
+	var _loadInfoMethods = {};
+
 	// Privileged methods
 	this.getName = getName;
 	this.getID = getID;
@@ -59,6 +61,7 @@ Zotero.ItemFields = new function () {
 	this.init = async function () {
 		_fields = {};
 		_fieldsFormats = [];
+		_loadInfo = [];
 		
 		var result = await Zotero.DB.queryAsync('SELECT * FROM fieldFormats');
 		
@@ -123,6 +126,57 @@ Zotero.ItemFields = new function () {
 	}
 	
 	
+	/**
+	 * The lookups Zotero.Item#setField() does for every value loaded from the
+	 * database, cached per item type and field
+	 *
+	 * The cache is dropped if any method it depends on is replaced, so an
+	 * overridden method is still consulted.
+	 *
+	 * @param {Integer} itemTypeID
+	 * @param {Integer} fieldID
+	 * @return {Object|false} - false for an unknown field
+	 */
+	this._getLoadInfo = function (itemTypeID, fieldID) {
+		if (_loadInfoMethods.getID !== this.getID
+				|| _loadInfoMethods.getFieldIDFromTypeAndBase !== this.getFieldIDFromTypeAndBase
+				|| _loadInfoMethods.isValidForType !== this.isValidForType
+				|| _loadInfoMethods.isMultiline !== this.isMultiline
+				|| _loadInfoMethods.getItemTypeID !== Zotero.ItemTypes.getID) {
+			_loadInfo = [];
+			_loadInfoMethods = {
+				getID: this.getID,
+				getFieldIDFromTypeAndBase: this.getFieldIDFromTypeAndBase,
+				isValidForType: this.isValidForType,
+				isMultiline: this.isMultiline,
+				getItemTypeID: Zotero.ItemTypes.getID
+			};
+		}
+		var byField = _loadInfo[itemTypeID];
+		if (!byField) {
+			byField = _loadInfo[itemTypeID] = new Map();
+		}
+		var info = byField.get(fieldID);
+		if (info === undefined) {
+			if (!this.getID(fieldID)) {
+				info = false;
+			}
+			else {
+				let resolvedID = this.getFieldIDFromTypeAndBase(itemTypeID, fieldID) || fieldID;
+				info = {
+					fieldID: resolvedID,
+					titleID: this.getID('title'),
+					valid: this.isValidForType(resolvedID, itemTypeID),
+					multiline: this.isMultiline(resolvedID),
+					isISBN: resolvedID == this.getID('ISBN')
+				};
+			}
+			byField.set(fieldID, info);
+		}
+		return info;
+	};
+
+
 	/*
 	 * Return the fieldName for a passed fieldID or fieldName
 	 */
diff --git a/chrome/content/zotero/xpcom/data/items.js b/chrome/content/zotero/xpcom/data/items.js
index dd35b89a53..f98b5eadcc 100644
--- a/chrome/content/zotero/xpcom/data/items.js
+++ b/chrome/content/zotero/xpcom/data/items.js
@@ -298,6 +298,7 @@ Zotero.Items = function () {
 		var sql = "SELECT itemID FROM items WHERE libraryID=?" + idSQL;
 		var params = [libraryID];
 		var allItemIDs = [];
+		var fieldIDsByType = new Map();
 		await Zotero.DB.queryAsync(
 			sql,
 			params,
@@ -306,9 +307,13 @@ Zotero.Items = function () {
 				onRow: function (row) {
 					let itemID = row.getResultByIndex(0);
 					let item = this._objectCache[itemID];
-					
+
 					// Set nonexistent fields in the cache list to false (instead of null)
-					let fieldIDs = Zotero.ItemFields.getItemTypeFields(item.itemTypeID);
+					let fieldIDs = fieldIDsByType.get(item.itemTypeID);
+					if (!fieldIDs) {
+						fieldIDs = Zotero.ItemFields.getItemTypeFields(item.itemTypeID);
+						fieldIDsByType.set(item.itemTypeID, fieldIDs);
+					}
 					for (let j=0; j<fieldIDs.length; j++) {
 						let fieldID = fieldIDs[j];
 						if (!itemFieldsCached[itemID] || !itemFieldsCached[itemID][fieldID]) {